Concept of Operations for the IH-10 Corridor in San Antonio, Texas

1.0 SCOPE

1.1 Project Identification

This Concept of Operations (COO) was developed under the project titled “TransGuide Integrated Corridor Management – Stage 1” as part of the Federal Highway Administration’s (FHWA) Integrated Corridor Management program.

1.2 Integrated Corridor Management (ICM) Background

Congestion in U.S. metropolitan areas is a serious and growing problem. Transportation agencies have typically implemented traffic management policies and strategies to improve mobility and reliability on a specific network, e.g., expressway, instead of looking at the entire transportation system across multiple transportation networks. Integrating traffic management strategies with adjacent networks, e.g., arterials and public transit, within a corridor will provide opportunities for transportation authorities to maximize mobility across the combined transportation networks. ICM is the “next generation” of transportations strategies to reduce congestion. ICM will be implemented by using improved individual network traveler information data and integrated operational procedures. For the individual traveler’s experience, ICM will result in reduced congestion and mobility and will make travel times more reliable and predictable. In addition, ICM will result in improved incident management and a reduction of incidents, lower emissions, and reduced fuel consumption.

1.3 Document Purpose

The purpose of the document is to capture the view of ICM operations from the user’s perspective. The document is a valuable and essential part of the system engineering process as part of the ICM project to improve quality and efficiency in implementing the ICM corridor in the San Antonio region. The document captures the operational concept to communicate the information to stakeholders. Through revisions, the Concept of Operations document has provided a mechanism for obtaining feedback and refining the concept.

1.4 COO Working Group Meetings

This document was developed in coordination with multiple transportation agencies within the San Antonio region. Three stakeholder working group meetings were held to discuss the COO for ICM in the proposed corridor. The dates of the meetings along with a summary of what was discussed are listed below.

Meeting 1 – December 18, 2006:

The main purpose of this working group meeting was to give an overview of the COO. Stakeholders discussed current issues and needs, as well as potential for ICM in the proposed corridor. During this meeting, stakeholders also discussed the tactics and approaches that could be used in the ICM concept.

Meeting 2 – January 26, 2007:

The main purpose of this meeting was to define the goals and objectives of ICM in the proposed corridor. The issues and needs discussed in the first meeting were reviewed, as well as the approaches and tactics. This meeting was also used to discuss and define performance measures and targets that could be used to measure the effectiveness of the ICM approaches and strategies.

An additional working group meeting is being scheduled in February to review the operation scenarios that will be described in Section 3.0 of this document.

Meeting 3 – February 20, 2007:

This meeting was used to discuss and review ideas for the operational scenarios to be included in the COO. Three sample scenarios were reviewed and refined, and possibilities and details for the remaining scenarios were discussed. This meeting was also used to finalize the list of network tactics that would be included as well as to go over any unresolved issues from the previous meetings.

1.5 Document Overview

The TransGuide™ ICM COO document provides an overall vision and description of how ICM will be implemented in the San Antonio IH 10 corridor. Section 1.0 provides the scope of the document. Section 2.0, Operational Concepts, first provides a background description of the stakeholders, corridor, individual transportation networks, and needs. In addition it provides and documents the vision of how ICM operations will occur within the corridor. Section 3.0, Supported Operations, describes a number of operational scenarios that provide working examples of how ICM operations will occur in specific circumstances. Section 4.0 lists the functional requirements for ICM in the corridor. Section 5.0 documents the traceability for the requirements. Notes are included in Section 6.0.

1.6 References

This section lists the documents referenced in this COO.

2.0 OPERATIONAL CONCEPTS

This section describes the operational concepts of the San Antonio integrated corridor, including the background and description of the corridor and participating agencies, operational policies and constraints, and supported operations.

2.1 Scope

San Antonio, Texas was selected as one of eight ICM pioneer sites for the development of COO, corridor data modeling, and development of functional requirements. This COO document was developed in coordination with the San Antonio ICM team which includes the Texas Department of Transportation (TxDOT) San Antonio District as the lead agency. Additional stakeholders include the City of San Antonio (CoSA), VIA Metropolitan Transit (VIA), Southwest Research Institute® (SwRI®) and the Texas Transportation Institute (TTI).

2.2 Background

The following section describes the background and description of the corridor and participating agencies.

2.2.1 ICM Corridor Boundaries, Networks and Stakeholders

The stakeholder team has selected a corridor in the northwest area of the San Antonio region for modeling and demonstration of ICM. The corridor was selected because it connects major workplace concentrations and the downtown region of San Antonio. IH 10, the major expressway route around which the corridor was developed, handles approximately 190,000 vehicles a day. In addition to the traditional expressway services available, the corridor has major signalized arterials that can be used to traverse the same geographic area. Bus transit, which uses both expressways and arterials, is available to reach a multitude of destinations within and beyond the corridor.

The IH 10 ICM Corridor is composed of three main transportation networks: an expressway network, an arterial network, and a transit network. A summary description of all the networks in the corridor is shown below.

The stakeholders involved in the development of this COO are listed in Table 1.

2.2.2 Corridor Operating and Institutional Conditions

The proposed corridor provides transportation for the movement of commuters, freight, recreational, and other traffic within and through the populous northern section of San Antonio. Traffic congestion along the roadway-based networks is a growing problem in the IH 10 Corridor, particularly during the peak periods. Some specific issues are listed below.

To help reduce the amount of congestion and improve traffic flow, each of the transportation agencies located in the corridor have implemented several different approaches to improve the performance of their networks. A summary of the approaches used by each agency is shown in Table 2.

However, in the past there has been little information and decision sharing across different agencies, with the exception of major events and incidents.

Although there is not a history of routine cooperation in the corridor, the capability is in place to allow for information sharing and a more ICM procedure.

2.2.3 Need and Potential for ICM

The IH 10 corridor is affected by several unique issues that have made it a prime candidate for ICM. The corridor links the downtown San Antonio central business district with residential areas, regional commercial development, educational institutions, and the medical center complex in the northwest quadrant of San Antonio. In addition to the normal business activity in the central business district, downtown San Antonio is the location of the Riverwalk (the most visited tourist destination in Texas). Within the ICM corridor there are additional major attractions including Six Flags Fiesta Texas, The Rim (retail and commercial development), the UTSA and the Shops at La Cantera, which also attract numerous visitors. Along the western portion of the corridor, there are other major traffic generators that include the South Texas Medical Center, the United States Automobile Association (USAA) headquarters and Valero Energy Headquarters. These various locations are linked by the IH 10 corridor.

To improve on existing network operations and to manage the proposed corridor from an integrated multi-modal approach, several needs that could be addressed with the Integrated Corridor Management Services (ICMS) concept were identified. The needs were gathered in workshops and in one-on-one meetings with the participating stakeholder agencies. These needs are summarized in Table 3.

2.2.4 Network Vision, Goals and Objectives

In order to develop an ICM vision and objectives that encourage buy-in and support from each stakeholder’s leadership, individual agency goals and objectives have been reviewed by the stakeholder team and are summarized below.

TxDOT Agency Goals

The TxDOT mission and vision statements are provided below.

The VIA mission statement and goals from the year 2005 plan are below.

City of San Antonio Public Works

The City of San Antonio Transportation Group, including the Traffic Engineering, Operations, and Management Organizations, are part of the city’s Public Works Department. The mission statement for the Public Works Department is below.

The following common themes have been identified from these mission statements and agency goals:

These themes and the agency mission statements and objects have been utilized to develop the ICM objectives for the IH 10 Corridor. The overall ICM Vision for San Antonio and these objectives are described in Section 2.3.1.

2.2.5 ICM Operational Approaches and Strategies

During stakeholder meetings and workshops, the stakeholders identified several strategies that could be used to achieve the goals and objectives identified for the proposed corridor. These strategies were categorized into the following ICM approaches.

2.2.7 ICM Implementation Issues and Required Assets

Each of the agencies involved in the ICM have various policies and technologies in place to improve the quality of their networks. However, to support the proposed strategies and tactics described for the ICM, additional assets and resources will be necessary. The proposed changes for each network are listed in Table 4. The changes and additions listed in the table as well as any other “unknown” changes will be utilized in the component and systems design processes.

2.2.8 Network Vision, Goals and Objectives

The stakeholders of the San Antonio region integrated corridor include:

A key to the success of the San Antonio regional ITS management is that the above team is comprised of organizations/agencies that have been working together for years to develop and maintain ITS systems in the San Antonio region. TransGuide has been nationally recognized many times for excellence in ITS and the staff we are proposing have had an active role in the current operational environment.

The TxDOT San Antonio District TransGuide Traffic Management Center provides the ITS management facility. The CoSA and VIA Metropolitan Transit (both of which have offices at TransGuide) provide program support in the areas of signals and bus transit. TxDOT in San Antonio has an interagency agreement with the TTI to provide specialized technical support and transportation operations technology transfer. Under this agreement, TTI provides the District with assistance in data collection, traffic simulation and analysis, and project benefit analysis studies. The San Antonio District of TxDOT also has a contract for engineering services with SwRI. Under this contract, SwRI acts as TxDOT San Antonio’s software and system development and integration consultant. Both SwRI and TTI are available for use by TxDOT for this effort. The CoSA has a contract for traffic engineering services with Post, Buckley, Schuh and Jurnigan (PBS&J).

The above representatives form the San Antonio ITS Technical Committee. The San Antonio Technical Committee establishes policy, operational procedures, executive leadership and oversight. In addition, the San Antonio Technical Committee develops inter-agency agreements and manages fiscal and infrastructure planning. The existing committee regularly coordinates transit operations that may affect operational, technical or political issues for one or more agencies. The stakeholders coordinate efforts in a joint and integrated manner, and the familiarity and relationship foundation already in place between stakeholder agencies will enhance and ultimately promote the success of the ICM plan for the San Antonio region.

2.2.9 Existing Corridor Scope and Operational Characteristics

The following sections describe the existing corridor and operational characteristics prior to ICM operations.

2.2.9.1 Corridor Boundaries and Networks

The San Antonio area has a unique expressway configuration in that there are three loops (one around downtown, Loop IH 410 about 7 miles from downtown and Loop 1604 about 15 miles from downtown) with four major interstate or US highways acting as radial expressways interconnecting the loop expressways (IH 10, IH 35, IH 37, and US 90). Figure 1 below is a high level graphic of the expressway infrastructure in the San Antonio area.

Figure 1. San Antonio Expressway Infrastructure. Source: Microsoft MapPoint

As Figure 2 shows, the San Antonio ICM team has selected a 15-mile expressway and arterial corridor along IH 10 from the IH 35/IH 10 Interchange in downtown San Antonio to the Loop 1604/IH 10 Interchange in northwest San Antonio. The IH 10 ICM corridor is bound on the west by State Highway (SH) 16 (Bandera Road) and on the east by Farm-to-Market (FM) Road 1535 (Northwest Military Highway). IH 10 runs roughly a southeast to northwest direction in the corridor area.

Figure 2. Proposed San Antonio ICM Corridor. Source: Texas Department of Transportation

As described earlier, the corridor includes one major longitudinal expressway (IH 10) as well as several arterials including Fredericksburg, Vance Jackson, Northwest Military Highway, Babcock, and Bandera. Expressways providing cross connectivity include Loop 1604 and Loop 410. Arterials providing cross connectivity include De Zavala, Huebner, Wurzbach, and Callaghan. The corridor boundaries in Figure 2 cover some of the most important, prevalent travel patterns (both recurrent and non-recurrent) as well as major highway, arterial, and transit facilities in northwest San Antonio. The boundaries, however, are preliminary. The final boundary selection will be made in conjunction with the U.S. Department of Transportation, taking into account a variety of factors such as Stage 2 modeling/simulation capabilities/requirements, and nature and characteristics of potential events to manage (the larger the event, the larger the area potentially impacted, which obviously has an effect on management area boundaries).

The IH 10 ICM Corridor encompasses a variety of land uses such as residential, commercial, industrial, and institutional. The corridor includes several major traffic generators, including the Loop 1604 and Downtown campuses of UTSA, the corporate headquarters of USAA and Valero Energy, the South Texas Medical Center, and downtown San Antonio. Other important transportation destinations include Crossroads Mall (IH 10 @ Loop 410) and The Rim and Shops at La Cantera (IH 10 at Loop 1604), as well as tourist attractions (e.g., Six Flags Fiesta Texas just outside Loop 1604 and the Riverwalk and the Alamo in the downtown area). Over the last several decades, major changes in land use have also occurred, where urban commercial and residential development, which was primarily confined to the area inside Loop 1604 through the early 1990s, has extended well beyond Loop 1604. Concomitant increases in commuting and retail activity have resulted in additional traffic demand along both expressway and arterial networks.

The IH 10 ICM corridor is one of San Antonio’s most heavily traveled corridors and is steadily increasing due to the growth along the corridor and continuing west. As an illustration, Table 5 summarizes Average Annual Daily Traffic (AADT) numbers observed on the corridor in 2004. Table 6 shows the average travel time index for am and pm peak times as well as the overall daily average travel time index in 2006. A travel time index is the ratio of the average peak period travel time as compared to a free-flow travel time. Over the years, transit service has also expanded to meet commuting and educational trips needs, and now includes park-and-ride service at IH 10 and Loop 1604, IH 10 and Loop 410 (Crossroads Mall), Loop 410 and Bandera Road, and downtown San Antonio. Express bus routes include service between the UTSA IH 10 at Loop 1604 campus and the UTSA downtown campus at IH 10 just west of downtown.

VIA also has two Park and Ride locations (Crossroads and University) and one transit center (Medical Center) within the ICM boundary. There are also three additional timed transfer locations (Deco District, Silicon/DeZavala, Bandera/Mainland) in the boundary where several routes meet for a “pulsed” departure. Figure 4 shows the location of major transit routes and facilities within the IH 10 ICM Corridor.

Figure 4. Bus Routes within the IH 10 ICM Corridor. Source: Texas Department of Transportation

In cooperation with VIA, TxDOT and the City of San Antonio, Bus Rapid Transit (BRT) is planned for deployment along Fredericksburg Road though the length of the corridor. The project will not be completed until 2012. Therefore, BRT will not be utilized in the near-term ICM deployment but will be utilized once it is operational. BRT will provide a transit alternative with improved travel times along the city’s most used transit corridor.

As the construction of the BRT line on Fredericksburg Road is nearing completion, routes along the ICM Corridor will be interlined to connect to the BRT at key stations. Planning already is underway for these service changes, as well as additional feeder and circulator services, that will connect to the BRT and be operational within the next five years. Also, during the next five years, VIA is working to increase the capacity and hours of service within the ICM Corridor. Twenty-four hour service is provided within the ICM Corridor inside Loop 410 and outside Loop 410 within the South Texas Medical Center area through a contract taxi service.

VIA also is currently studying where additional park and ride lots are needed within the ICM Corridor. Minimal, if any, parking is planned at most BRT stations, as the BRT will operate in a built up urban environment. Exceptions may include the two stations at the end of the BRT starter line, and at Crossroads Mall, where VIA is looking to move an existing park and ride lot so that it would be adjacent to the BRT line. VIA currently has adequate excess parking capacity at existing park and ride lots within the ICM Corridor, but is currently examining a potential move or expansion at the University Park and Ride lot at I-10 and Loop 1604. Additionally, express service is being planned to connect the end of the BRT starter line to UTSA's main campus.

2.2.9.2 Corridor Stakeholders

The ICM stakeholders for the corridor are listed in Table 8. All of the stakeholders on the list played some part in the development of the ICM concept, but not all are responsible for an individual network existing in the corridor. Stakeholders responsible for a network are marked with an asterisk and the network they are responsible for is shown in parenthesis.

2.2.9.3 Operational Conditions of the Corridor and Included Networks

The IH 10 Corridor provides transportation for the movement of commuter, freight, recreational, educational and other traffic, and contains some of the most highly congested expressway segments in all of San Antonio.

When Table 6 is compared to the San Antonio area wide travel time index, shown in Table 9, most of the travel time indexes within the corridor are either average or higher when compared to the rest of San Antonio. This table also shows that the total congestion time, travel time index and planning time index have all risen since the beginning of 2006.

Table 9. San Antonio City Wide Congestion Indicators. Source: Texas Transportation Institute.

The most congested expressway segment, as well as four of the top ten congested expressway segments in San Antonio are located within the IH10 ICM corridor. As can be seen from Table 10, these top expressway segments all have major declines in average speed and increases in volume during peak travel periods. These figures show that there is a very real potential for congestion improvement within the corridor.

Table 10. Top Congested Corridor Segments (Avg. Speed and Volume)

		Average Speed (mph)*		Average Volume (vehicle/hr)*
Segment Description	Miles	Weekday Peak	Weekend All Day	Weekday Peak	Weekday All Day
IH10WB: I-35/I-10 Jct. to Loop 410	8.1	51.36	56.11	16200	13968
Loop 410 WB: I-35 to IH10	9.8	52.13	54.89	37296	34158
IH10 EB: Loop 1604 to Loop 410	8.8	53.84	59.94	36402	30114
Loop 1604 EB: Bandera Rd to Lockhill-Selma	6.3	54.30	60.94	14622	12553

Arterial roadways within the corridor also have many congested segments. Figure 5 shows some of the more congestion roadways within the corridor, as well as showing that much of the ICM corridor is perceived by San Antonio travelers to be heavily congested.

Figure 5. Area Wide Congestin Map. Source: Texas Department of Transportation

This congestion has a severe effect on commuter traffic within the corridor, as well as affecting transit travel times. Table 11 shows the peak travel times for major transit routes within the corridor. When compared with the non-peak travel times, it can be seen that the congestion has a major effect on transit routes as well.

The significant level of commuter traffic within the corridor results in significant peaking characteristics for both roadways and transit. The travel market within the IH 10 Corridor consists of the following trip types:

• Users with trips originating either in the corridor with a destination outside the corridor or outside the corridor with destinations within the corridor.

• Users traveling within the corridor on local trips (i.e., both origin and destination within the corridor).

• Traffic passing through the corridor (i.e., with neither origin nor destination in the corridor) to access or pass through the central business district.

Traffic congestion along the roadway-based networks is a growing problem in the IH 10 Corridor, particularly during the peak periods. The congestion problems have resulted in a number of serious issues, such as loss of personal and professional time, increased fuel consumption, increased accident rates, environmental degradation, and traveler frustration. As congestion and delays have increased, actual throughput corridor-wide has declined.

Recent studies of the expressway operations indicate that congested conditions (i.e., average speeds of less than 40 miles per hour) typically exist during four hours of every workday: two during the AM peak, and two during the PM peak. The cause of this expressway congestion can be attributed to the following factors:

All of these factors contribute to congestion issues throughout San Antonio, with many problem areas existing within the ICM corridor. These issues are also gradually becoming worse throughout the San Antonio area. As show in Figure 6, the San Antonio wide travel time index, as well as the planning time index, has been slowly rising since 2004, with an even greater rate of increase since fall of 2006. Through the use of ICM concepts and strategies, it is believed that these trends can be slowed and maybe even reversed in the ICM corridor, thereby lowering the overall averages of all San Antonio traffic.

Figure 6. Area Wide Congestion Trends since April 2004. Source: Texas Department of Transportation

2.2.9.4 Existing Network-Based Transportation Management/ITS Assets

The following sections describe the existing infrastructure that has been established by the agencies that make up the San Antonio team.

TransGuide

TransGuide is the Advanced Traffic Management System (ATMS) for the TxDOT San Antonio District and provides centralized traffic management for San Antonio’s limited access expressways. This includes IH 10 which will be the primary network for moving goods and travelers through San Antonio’s proposed ICM corridor. TransGuide has been operational since July 26, 1995. It is located centrally on the IH 10 corridor on the north side of downtown San Antonio at the intersection of IH 10 and Loop 410. This location is centralized with the population growth of San Antonio and to the instrumented roadways operated by TransGuide.

Initially when TransGuide became operational, it was responsible for managing 26 miles of expressway. Currently, the full TransGuide ATMS system is in place on 93 miles of expressways in the San Antonio area (fiber communications, CCTV cameras, speed sensors, etc.). An additional 60 miles of expressway is instrumented with speed sensors only. Expansion of the TransGuide system is ongoing, with approximately 9 additional miles currently under construction.

The TransGuide network utilizes a number of devices to instrument the expressway including a variety of sensors to collect speed, volume, occupancy data, CCTV cameras, DMSs, and LCSs. The goal of this instrumentation is to provide incident detection, verification, and response. Table 12 lists the device type and number currently deployed by TransGuide.

TransGuide uses a combination of inductive loops, radar detectors and VIVD sensors to collect traffic conditions data on a lane–by-lane basis approximately every half mile for the 150 miles of the network. The speed, volume, and occupancy data gathered from these sensors is collected by the central ATMS software every 20 seconds. A two-minute rolling average of traffic conditions is evaluated and when conditions are worse than acceptable thresholds, the TransGuide operations staff is automatically alarmed by the ATMS system. The operations staff utilizes the CCTV cameras to verify that the incident exists and to evaluate the appropriate incident response including the emergency response and changes to DMS messages or LCS signage.

The continued growth of the TransGuide infrastructure is planned with a goal to provide coverage of over 289 miles of expressway. In the near term, TxDOT is planning the following modifications to be completed in the next two years:

CoSA Signal System

The CoSA currently has coordinated traffic signal systems along the Fredericksburg Rd.-Huebner Rd., De Zavala Rd., Wurzbach Rd.-Vance Jackson-Lockhill Selma and Babcock-Wurzbach Rd. corridors. The details of these systems are shown in Table 13.

Currently, these traffic signal systems are managed principally through dial-up communications to the traffic signal controllers. CoSA is currently designing an improved communication network plan to provide high-speed network connectively to each of its signals. Completion for the network in the San Antonio central business district is scheduled for the summer of 2008. Substantial completion of the network to provide access to the CoSA traffic signals is scheduled for completion between 2009 and 2011 with an emphasis placed on the corridor where possible.

Signal timings are downloaded and signal operation reports are uploaded from the Fredericksburg Rd. signal system intersections. Current monitoring capabilities of the system allow traffic management and traffic signal maintenance staff to perform preliminary trouble shooting before dispatching signal maintenance technicians to the intersections. The existing central traffic signal control software also allows access to real-time intersection displays, selection of timing parameters, alarm history, operating history, detector counts, split monitor reports, and other information. Intersection timing parameters or system-wide timing plans can be uploaded and downloaded from the CoSA TMC.

VIA AVL System

VIA employs an AVL system for tracking the location of the vehicles in its fleet. The real-time tracking information provided by the AVL system is utilized to adjust bus scheduling and routes, and to dispatch maintenance, security, and administrative vehicles. VIA currently has 761 vehicles in its fleet that are AVL equipped:

VVIA also has onboard video systems installed on nine buses and ten vans at the present time. VIA plans to equip the entire fixed route and paratransit fleet with the onboard video system within the next year. This system is used for security of the bus fleet and its drivers.

The AVL system provides the actual location by latitude/longitude and is accurate to within 6 meters. Data from the AVL system (logged events) are available in a report format and can be run by the day, week, month, or on an annual basis. The video images from the onboard video system are stored on an internal hard drive on the vehicle that is configured to write protect an event if the operator presses the “Covert Alarm” so that the data is saved.

The AVL system is monitored from the Dispatch Center, Maintenance, and IT groups. The central dispatching and operations of the VIA fixed route buses is performed from three Dispatch workstations on the TransGuide operations floor. VIA works closely with TransGuide operations staff to share incident information. In addition, VIA’s dispatch center for paratransit vans is located in the TransGuide operations center in a separate office space. VIA uses the AVL information at both the TransGuide operations dispatch workstations and in the paratransit dispatch office to monitor radio communications, route schedule information, vehicle status and other events such as improper or dual log on.

The AVL network information is also available to the AVL network management team. The AVL network management team includes the manager of ITS, an AVL technician, a radio specialist and two programmers within the IT Division located at VIA’s headquarters. The AVL information is used to maintain and oversee the operation of the deployed system from a maintenance and an IT perspective.

To ensure reliable AVL data is captured in the case of communications issues, VIA utilizes an onboard unit to capture events at a 60 second interval and record them on a memory card. The day’s events are then downloaded via the Wireless LAN located in the central VIA bus yard. If there is a total onboard system failure data would not be gathered nor transmitted from that specific vehicle and the dispatcher would attempt to perform a vehicle change out. Preventive maintenance is linked with the normal service intervals for the vehicles by the Maintenance Department.

VIA completed an upgrade to the AVL software and is initiating the planning and implementation of “On Street Passenger Information Signs” at select park and ride, transfer centers and high yield stops. The On Street Passenger Information Signs will provide VIA customers with up to date information on the arrival of a specific bus for the assigned route.

Emergency Operations Center (EOC)

Bexar County and CoSA, under the direction of the San Antonio Fire Department, with significant involvement from San Antonio Police Department (SAPD), are currently organizing and building a new EOC to provide emergency response coordination from multiple agencies including SAPD, TxDOT, CoSA, Fire, EMS, and the military. The EOC will be responsible for coordinating local operations during hurricane evacuations, terrorist attacks, flooding, or other city-wide impacting emergency events. Hurricane evacuations have had a significant recent impact in San Antonio as the city is the first major metropolitan area for handling evacuations from Houston, Corpus Christi, and the southern Texas populous. The EOC is currently scheduled for completion and to begin operation in November of 2007.

For effective management of the proposed San Antonio ICM corridor, TxDOT proposed coordination with the EOC to handle major corridor affecting incidents. For example, such events could include hurricane evacuations or long-term road closures involving a hazardous material spill. TxDOT is proposing that a TransGuide console be integrated into the EOC to provide access to TransGuide video and execute an incident response on DMS and LCS signage. The TransGuide EOC console will also provide a backup control center in case of an event that resulted in the closure or evacuation of the TransGuide facility.

2.2.9.5 Proposed Near-Term Network Improvements

There are currently several improvements underway or in planning for the major networks within the region. These improvements and changes will have a direct impact on the ICMS and must be taken into account during design and planning. The improvements that affect the corridor are listed in Table 14 and are organized by network.

2.2.9.6 Regional ITS Architecture Review

The San Antonio ICM team has conducted a high-level overview of the San Antonio regional ITS Architecture. The regional architecture provides a means for effective planning and management of ITS approaches and assets within the San Antonio Region. The ICM approach provides a broader view of transportation management. The Regional ITS Architecture provides detailed guidance for implementation and development of regional transportation management.

As of this writing, the San Antonio Regional Architecture is under revision. The San Antonio ICM corridor committee will provide input to this revision to ensure ICM is considered in the ITS Architecture. The opportunity exists to integrate ICM and regional ITS Architecture concepts to provide a blended regional transportation plan. The IH 10 corridor development project will provide ICM concept inputs to the Regional ITS Architecture development team. The current anticipated changes to the Regional ITS Architecture fall into the following areas:

2.2.9.7 Individual Network and Corridor Problems, and Issues

Each network in the corridor has certain problems and issues that affect their overall success. Two major issues that affect each of the networks are listed below.

During several meetings and workshops, the stakeholders also identified additional issues and needs that involved individual networks, as well as the corridor as a whole. These needs that were derived from these issues are summarized in Table 3

2.2.9.8 Potential for ICM in the Corridor

The IH 10 corridor is affected by several unique issues that make it a prime candidate for ICM. The corridor links the downtown San Antonio central business district with residential areas, commercial development areas, educational institutions, and the medical center complex in the northwest quadrant of San Antonio. In addition to the normal business activity in the central business district, downtown San Antonio is the location of the Riverwalk (the most visited tourist destination in Texas) and the Alamo. Six Flags Fiesta Texas, The Rim, UTSA, and the Shops at La Cantera, which also attract numerous visitors, are all located along the corridor. These locations are linked by the IH 10 corridor. Other major traffic generators in the corridor area include the South Texas Medical Center, the USAA headquarters and Valero Energy headquarters.

Current and planned construction projects along IH 10 impact the traveling public on a daily basis. Currently, the IH 10/Loop 410 Interchange is under construction. This project includes the construction of eight direct connecting ramps and the widening of the main lanes of both expressways. The interchange project construction is anticipated to be complete in late calendar year 2007. IH 10 is being widened between Loop 410 and the downtown area, from three lanes per direction to five lanes per direction. This project includes the reconstruction of all grade separated intersections along the corridor. These signalized intersections have been operated historically by TxDOT, but as part of the current construction, they will be built to CoSA specifications and turned over to the CoSA for operations and maintenance following the conclusion of the project. Construction will begin in early 2007 on IH 10 from Huebner Road to UTSA Boulevard, just south of the IH 10/Loop 1604 interchange. This project is being done to support the planned construction of a tolled managed lane system on Loop 1604, which will include the reconstruction of the IH 10/Loop 1604 interchange. The Huebner to UTSA project will also include intersection improvements that will allow TxDOT to transfer ownership and operation of the signalized intersections to CoSA.

TxDOT is responsible for roadway maintenance for arterial roadways that are on the state highway system. However, per Texas state law, for arterials in cities with populations greater than 50,000 the city is responsible for operation of the traffic signals after they have been constructed by TxDOT. For communities with populations less than 50,000, TxDOT continues to operate the traffic signals following construction. In the corridor area, Fredericksburg Road is on the state highway system (Spur 345), as are Northwest Military Highway (FM 2696) and Bandera Road (SH 16). Fredericksburg Road intersects IH 10 near the downtown IH 10/IH 35 interchange and parallels IH 10 to the west for approximately nine miles. The traffic signals at the near downtown Fredericksburg Road/IH 10 signalized intersection are operated by TxDOT. The signalized intersections along Fredericksburg Road are operated by CoSA. However, through a small community located near the IH 10/Loop 410 interchange, Balcones Heights, the Fredericksburg Road signals are operated by TxDOT. TxDOT uses NEMA controllers, and CoSA currently uses 170 controllers, with plans to begin upgrading to 2070 controllers. Thus coordination of the traffic signals systems is a complex issue. TxDOT has historically operated the traffic signals at expressway frontage roads, but has turned several of the signals over to CoSA for operation to facilitate coordinated signal operation. As part of the current and planned expressway construction projects, responsibility for operation of additional/upgraded signals at frontage road intersections will be transferred from TxDOT to CoSA. Under the ICM project, the planned coordinated traffic signal operations will be facilitated, and the coordination of traffic signals across jurisdictional boundaries will be emphasized. Although no firm completion dates have been decided, the first communication infrastructure upgrades should begin in early 2008, with the downtown central business district being the first location, and the ICM corridor is a priority for selections after the business district is complete. There are also several city bond projects which will allow for upgrades and additional signals to be added in several different locations, with the initial planning for design complete in 2008. The 2070 signal upgrades are also scheduled to begin in 2008 with the ICM corridor again receiving a high priority.

2.3 Operational Policies and Constraints

TThe following sections document the Operational Policies and Constraints for implementing ICM within the IH-10 Corridor.

2.3.1 Corridor Vision and Mission

San Antonio stakeholders have developed the following ICM vision:

San Antonio ICM Vision

Provide seamless multi-model corridor operations to provide effective and reliable transportation by providing improved safety and incident management, and more persuasive and timely traveler information.

San Antonio is unique among the eight selected ICM Pioneer sites. It is clearly the smallest urban area of the selected ICM teams, being nearly half the size of the next largest ICM Pioneer site of San Diego, California. As the ICM approach to traffic management advances and the necessity for its use as a solution to combat growing congestion continues, San Antonio’s ICM pioneer site experience will be extremely valuable in shaping ICM concepts on a broad scale for a significant number of cities that are small and medium sized urban areas. Therefore, San Antonio’s mission as a Pioneer site is to be the model for ICM deployments in smaller to medium sized cities.

2.3.2 Corridor Goals and Objectives

Reviewing the individual stakeholder agency mission statements and objectives, a number of common themes were identified to develop the corridor goals and objectives. To achieve the San Antonio corridor vision, the following goals and objectives have been identified for the ICM approach in the San Antonio corridor:

Table 15 below maps each of the identified agency mission statement and goal themes to the corridor objectives. For example, improved traveler information and effective and reliable transportation across multiple networks will allow for more flexibility in a choice of transportation mode.

2.3.4 Comparison of ICM Concept Asset Requirements with Current and Potential Assets

Based on what will be necessary to implement the proposed tactics and reach the goals of ICM, each organization will need some additions or improvement to their existing networks. There will also be a need for a better integration between these existing networks. The major improvements and additions that will be necessary are shown in Table 18. Items highlighted in grey are already in progress, or are scheduled to begin soon. The remaining items, as of now, do not exist, and are not scheduled as part of a near-term existing project. However, these items will be required for the ICM strategies and will be completed as necessary.

Table 18. Comparison of Corridor Assets with ICM Needs and Issues

	TxDOT	CoSA	VIA
Expansion of CoSA Traffic Signals	N/A	38 additional frontage road traffic signals under construction and will be converted to CoSA standards  Remaining signals will be converted as funding allows Key TxDOT signals will be turned over to CoSA to provide seamless operation between IH-10 and Loop 410 Red light enforcement cameras will be placed at selected major intersections Area wide fiber and communications sharing that will allow CoSA’s signal controllers to use TransGuide’s network to transmit control data to the CoSA system at TransGuide	N/A
Entrance Ramp DMS	Create an interface from the CoSA signal operations system to the TransGuide Data Archive to provide TxDOT and CoSA with combined intersection signal data and entrance ramp data Develop an application that will incorporate expressway travel times, adjacent signalized intersection delay calculations, entrance ramp traffic volumes and intersection traffic volumes in messages for Entrance Ramp DMS	N/A	N/A
Network Based ATIS	Create condensed version of website for use on PDA’s and other hand held devices	N/A	Install “On Street” Passenger signs that provide up-to-date bus arrival information  The first sign has been deployed with additional signs being deployed during late 2007 and 2008
Personal Emergency Transportation Plan	Develop integrated route planner with CoSA and VIA Construction of website used for creating and storing emergency transportations plans Develop publicity strategy to inform travelers of the site and how it can be useful	Develop integrated route planner with TxDOT and VIA Construction of website used for creating and storing emergency transportations plans Develop publicity strategy to inform travelers of the site and how it can be useful	Develop integrated route planner with CoSA and TxDOT Construction of website used for creating and storing emergency transportation plans Develop publicity strategy to inform travelers of the site and how it can be useful
Co-Location at TransGuide	N/A	Addition of Traffic Signal operator workstation on TransGuide operations floor	N/A
Enhanced Signal Control	N/A	Development of pre-planned signal timing patterns for possible incident scenarios Development of guidelines for selecting and implementing pre-planned signal timing patterns	N/A
Sharing of real-time data and joint use of data archive	Integration of CoSA data utilizing C2C standards Integration of VIA data utilizing C2C standards Integration of data from Computer Aided Dispatch (CAD) systems in the local municipalities (Balcones Heights, Castle Hills, Leon Valley, and Shavano Park)	Development of C2C software interface to integrate available CoSA data into TransGuide real-time data	Development of C2C software interface to integrate available VIA data into TransGuide real-time data
Expanded Congestion Management Program	Apply integrated arterial/frontage information for use in congestion messages.	Integration of CoSA arterial/frontage data into TransGuide’s real time data	N/A

2.3.5 Corridor Concept Operational Description

The IH-10 corridor consists of numerous agencies with unique and distinct corridor responsibilities. Leadership of the corridor will be conducted via the existing San Antonio ITS Technical Committee consisting of representatives from each of the corridor stakeholders. The committee’s charter is to provide corridor guidance, address fiscal concerns, plan corridor project development, provide transportation management integration, and promote transportation modal transition. The committee’s intent is to provide corridor executive oversight. Agency representatives are appointed by the committee to manage corridor daily operations.

Corridor operations are conducted at the central location of the TransGuide facility. This facility provides integration and control functionality required for successful management of the ICM concept. ICM operations and decisions are carried out in a similar manner to normal day-to-day operations. Agency integration exists to accommodate corridor wide decision support mechanisms for transportation management.

Agency representatives are appointed by the corridor committee for the purpose of overseeing daily operations. The corridor transportation issues are effectively coordinated by this committee. Each agency representative is responsible for providing the corridor support and interface to their respective agency accordingly.

As previously described, the TransGuide facility will host the corridor operations. Most decisions in relation to corridor operations will be managed through the TransGuide facility. Assigned agency staff is responsible for the daily operations, response scenarios, administration, and corridor improvement development. The TransGuide facility will maintain 24/7 operations on a normal basis. ICM agency representatives will monitor transportation fluctuations and implement scenarios, real-time decisions, and provide transportation guidance as required.

Performance measurement plays a key role in the development of the corridor. Integrated data mining and archiving conducted by the corridor management team will provide useful transportation management, transportation engineering and corridor trend models and reports to both the corridor committee and operations staff.

Operations, communications, software, voice and data systems will be integrated to facilitate decision support. A great deal of integration necessary to provide an improved decision support mechanism exists currently with the TransGuide system. Technology protocols will comply with NTCIP and C2C standards in place today. It is not anticipated that new standards will be developed for the sole purpose of the IH-10 integrated corridor.

A key focus of the corridor is to provide real-time transportation updates to the traveler. Traveler information will be updated via DMS message signs, TransGuide web page, small device updates and local media. The goal is to provide the traveler with enough information as to increase their awareness of transportation options and influence the traveler to choose different modes of transportation based on transportation conditions.

The San Antonio integrated corridor is envisioned as a seamlessly integrated operation. Improved mobility across the transportation networks is the primary objective. The intent is to mold the corridor user’s viewpoint into a perception that the IH-10 integrated corridor provides successful incident management, ease and frequency of modal shifts, and accurate and useful information.

2.3.6 Alignment with Regional ITS Architecture

The IH 10 integrated corridor team has conducted a high-level overview of the San Antonio regional ITS Architecture. As stated previously, the regional architecture provides a means for effective management of ITS assets within the San Antonio region. Major points of the assessment are as follows:

During the time this COO was developed, the San Antonio Regional Architecture was under revision by Kimley-Horn and Associates. The San Antonio corridor committee has provided input to this revision. The opportunity exists to integrate ICM and regional ITS Architecture concepts to provide a blended regional transportation plan. The current anticipated changes to the Regional ITS Architecture fall into the following areas:

Kimley-Horn and Associates have reviewed a preliminary revision of this COO. Kimley-Horn will ensure the upcoming revision of the San Antonio regional ITS architecture includes the necessary market packages to implement the proposed network and corridor tactics. The ICM effort with comply with the upcoming revision of the architecture that is expected to be completed in the summer of 2007. ICM is not intended to replace or conflict with established Regional ITS Architecture plans and procedures. In fact, the ICM concept is meant to enhance and supplement the Regional ITS Architecture. Future considerations made for the corridor must take into account and coordinate with the Regional ITS Architecture. An enhanced or integrated ICM and Regional ITS Architecture is meant to increase information sharing, agency inter-operability and system integration.

2.3.7 Implementation Issues

Implementation issues that could affect the successful ICM deployment have been identified below. In addition to the issues, a mitigation strategy has been developed to address the concerns. The San Antonio ITS Technical Committee will be responsible for reviewing the implementation risk and executing the mitigation strategy. When necessary, the mitigation strategy will be revised and adapted. As new implementation issues are determined, corresponding mitigation strategies will be developed and the issues will be tracked by the San Antonio ITS Technical Committee. Identified implementation issues fall into three areas: Operational, Technical, and Institutional.

Operational Issues

Operational issues affect corridor operational policies and procedures. This includes the operation of external agency devices, signal timing, and bus scheduling. Table 19 below lists the identified issues and corresponding mitigation strategy.

Technical Issues

Technical issues affect how corridor operations are implemented. Technical issues include system integration, hardware accessibility, protocol standards utilized, and other technological issues that prohibit information sharing or automated corridor operations. Table 20 below lists the identified issues and corresponding mitigation strategy.

Institutional Issues

Institutional issues relate to the interagency agreements and coordination that limit or prohibit the proposed corridor institutional coordination. Table 21 below lists the identified issues and corresponding mitigation strategy.

2.3.8 ICM Concept Institutional Framework

Implementation issues that could affect the successful ICM deployment have been identified below. In addition to the issues, a mitigation strategy has been developed to address the concerns. The San Antonio ITS Technical Committee will be responsible for reviewing the implementation risk and executing the mitigation strategy. When necessary, the mitigation strategy will be revised and adapted. As new implementation issues are determined, corresponding mitigation strategies will be developed and the issues will be tracked by the San Antonio ITS Technical Committee. Identified implementation issues fall into three areas: Operational, Technical, and Institutional.

A key to success of the proposed corridor is that the above team is comprised of organizations/ agencies who have been working together for years to develop and maintain ITS systems in the San Antonio region. The TxDOT San Antonio TransGuide office will provide the ICM facility and corridor project management. The CoSA and VIA Metropolitan Transit (both of which have offices at TransGuide) will provide major program support in the areas of signals and bus transit.

The above representatives will form the governing body. The forum of the San Antonio ITS Technical Committee will be used to provide recurring meetings with the identified stakeholders to establish policy and operational procedures and to provide executive leadership and oversight. In addition, the governing body will develop inter agency agreements and manage fiscal and infrastructure planning. Currently, the existing body regularly coordinates transit operations that may affect operational, technical, or political issues for one or more agencies. The stakeholders envision continuing coordinated efforts in a more jointed and integrated effort through the ITS Technical Committee. The familiarity and relationship foundation already in place between stakeholder agencies will enhance and ultimately promote the success of the ICM plan for the San Antonio region.

Table 22. ICM Stakeholder Responsibilities and Staffing

Agency/Service	Responsibilities	ICM Aligned Staff
San Antonio Integrated Corridor Command Center	• Coordinated operations • Corridor administration activities • Performance monitoring • Technical management and development • Data archiving and warehousing
EOC	• Coordinated operations during emergency situations (evacuation, natural disasters, etc.)
Texas Dept. of Transportation	• Daily corridor operations • Traffic expressway management • ITS device management • Implement response plans • Expressway maintenance	• Agency/Service officer, administration, and technical support staff
City of San Antonio	• Daily corridor operations • Manage surface roadway ITS devices • Implement response plans	• Agency/Service officer, administration, and technical support staff
VIA	• Daily corridor operations • Manage bus schedule timing • Implement response plans	• Agency/Service officer, administration, and technical support staff
San Antonio Police Dept.	• Law enforcement coordination • Incident response management	• Agency/Service officer, administration, and technical support staff
San Antonio Fire Dept.	• Emergency management	• Agency/Service officer, administration, and technical support staff
TTI	• Perform data analysis • Evaluate if performance measures have been met • Traffic planning studies
SwRI	• Systems engineering • Troubleshooting and support of operations automation • Conceptual planning

2.3.9 Performance Measures and Targets

In order to ensure that the San Antonio regional ICM deployment goals and objectives are met, performance measures and targets have been identified to objectively measure the success of the corridor. Table 23 below lists performance metrics that have been identified for each of the San Antonio corridor goals and objectives. These performance metrics will be monitored to evaluate the effectiveness in obtaining the ICM deployment goals.

The San Antonio ICM corridor committee will review the performance metrics on a regular basis, by default this will be performed quarterly. Based upon the review of the meansures and reports from ICM operations staff, adjustments in ICM operations and tactics will be made. Performance measure reports will be added to the TransGuide Data Archive to automate the extraction of the data. TTI and other IT staff will assist with the collation of the data into a meaningful format that can be evaluated by the ICM corridor committee.

In addition to the performance measures identified above, it is important to develop a standard performance measure that can evaluate the success of ICM strategies for the corridor as a whole. An industry standard for a cross-network corridor performance index does not currently exist. San Antonio proposes to utilize both a corridor travel time index and corridor buffer time index. Both corridor indexes will be based on the summation of the volume weighted average of each network’s respective index value. These performance measures will provide insight into both the mobility and reliability of the corridor, weighting the individual network’s contribution to the corridor based on the volume of travelers. The corridor performance metrics will be generated and evaluated quarterly. The following equation shows the CorridorTTIndex (Corridor Travel Time Index).

The following equation is for the CorridorBufferIndex (Corridor Buffer Time Index).

3.0 SUPPORTED OPERATIONS

This Concept of Operations (COO) was developed under the project titled “TransGuide Integrated Corridor Management – Stage 1” as part of the Federal Highway Administration’s (FHWA) Integrated Corridor Management program.

This section contains example scenarios for the ICM corridor and how the stakeholder organizations will respond to the described conditions. These scenarios are meant to show how the stakeholders within the corridor will use each of the suggested tactics and strategies to respond to traffic events that take place within and around the ICM corridor. Co-location in the TransGuide building allows for a very reliable and convenient channel of communication between agencies. TransGuide, VIA and SAPD all have stations on the operations floor of the building. This allows representatives from these three agencies to directly communicate with one another with very little effort, as well as providing each agency the ability to view live video from the TransGuide CCTV system. The City of San Antonio Traffic Management office is located on the second floor of the TransGuide building, and representatives from this office also have access to the operations floor when it becomes necessary. This co-location allows each of these stakeholder organizations to communicate continually during any operational scenario as well as during their respective daily operations.

The scenarios discussed in this section include the following:

3.1 Daily Operational Scenario

The daily operational scenario focuses on the typical day-to-day operations of each stakeholder organization and their corresponding management strategies. It does not involve any incidents, planned closures, or any other non-routine events that could have an impact on traffic flow and management (expressway, arterial or transit).

Each stakeholder organization will maintain their network according to the current regulations and policies, with an emphasis on information and data sharing. The sharing of data will be used to allow each organization to make the best possible decisions as to how to manage their respective networks, as well as provide a base that other management techniques may be built upon.

3.2 Scheduled Event Scenario

The planned event in this scenario is a work zone to repair bridge joints over Loop 1604 and Tradesman Rd. This will require closing of all eastbound lanes. This repair is scheduled to take place starting at midnight on Friday and conclude no later than 5:00 PM on Saturday. Advanced notice through the TxDOT Public Information Officer will be given to the media for distribution to the public so that travelers can make plans to avoid the closure, helping to alleviate congestion and backup during the actual closure period. Figure 16 shows a timeline of the events that will take place during the scheduled event.

Figure 16. Timeline for Scheduled Event. Source: Texas Department of Transportation

3.3 Incident Scenarios

The following sections describe various unplanned incidents in the corridor and their associated responses. Three scenarios are discussed, a minor and major expressway incident, as well as, a major arterial incident. Minor incidents have a delay of only a few hours and typically only affect one or two networks. Major incidents last for much longer periods of time and typically have an impact on all networks within the corridor.

3.3.1 Minor Traffic Incident Scenario

The following sections describe various unplanned incidents in the corridor and their associated responses. Three scenarios are discussed, a minor and major expressway incident, as well as, a major arterial incident. Minor incidents have a delay of only a few hours and typically only affect one or two networks. Major incidents last for much longer periods of time and typically have an impact on all networks within the corridor.

Figure 17. Timeline for Minor Traffic Incident. Source: Texas Department of Transportation

3.3.2 Major Traffic Incident Scenario

At 5:00 AM on a weekday, an eastbound tractor-trailer on IH 10 collides with an Overhead Sign Bridge (OSB) leg, causing it to fall onto the expressway. The initial towing away of the trailer will only take 1-2 hours, but the removal of the OSB structure will take an additional 10-12 hours. This will cause eastbound IH 10 to be closed for most of the day, including morning and evening rush hours. During the closure, traffic will be re-routed off the expressway onto either Fredericksburg Road or along the frontage roads. The stakeholder organizations will work together as described in the following section to help minimize traffic impact and delay. Figure 18 shows a timeline of events for this major traffic incident.

Figure 18. Timeline for Major Traffic Incident. Source: Texas Department of Transportation

3.3.3 Major Arterial Incident Scenario

At 10:00 AM on a weekday, a train derails on the railroad tracks running parallel to and east of IH 10. The train derails near the Huebner Road crossing and train cars are backed up to the Wurzbach Road crossing. Another train engine is being brought in to pull out the cars still on the tracks, which will take approximately 4-5 hours. Wurzbach Road will be blocked until this is complete. The derailed cars at the Huebner Road crossing will have to be lifted out of the way and this task will take an additional 5-6 hours. Once the crossing at Huebner is cleared and traffic may pass, the final stages of the incident clean up can take place. After both crossings are cleared the only impact to traffic will be residual effects until queues can be cleared.

During the initial phase when both crossings are closed, traffic will be re-routed to either DeZavala Rd. or IH 10 to Loop 1604 to move traffic across the boundary generated by the railroad tracks. Once on the east side of the tracks, Lockhill Selma Rd and Northwest Military Highway will become the primary arterials used for travelers to move north and south around the closed east and westbound arterials.

Once the train cars have been cleared from the Wurzbach crossing, Wurzbach Rd. will also be available for crossing the tracks, with Lockhill Selma and Northwest Military Highway remaining the primary arterials for travelers once they have crossed the tracks.

Figure 19 shows a timeline of events for this major arterial incident.

Figure 19. Timeline for Major Arterial Incident. Source: Texas Department of Transportation

3.4 Transit Special Event (Fiesta) Scenario

The special event depicted in this scenario is Fiesta. Fiesta is an annual week long festival in San Antonio that involves many different types of events at many different venues, mostly taking place around the downtown area. The five major events in Fiesta are Oyster Bake, the Flambeau Parade, the River Parade, Night in Old San Antonio (NIOSA), and the Battle of the Flowers Parade. Oyster Bake is a two day event on the St. Mary’s University Campus featuring music, food and games. NIOSA is a four night event along the River Walk with several different booths and music. The remaining events are parades that take place in different areas downtown, with the River Parade taking place through the River Walk. Throughout the event, VIA uses their Park and Ride facilities to bus passengers to and from each of the events. Within the span of the event, these park and ride facilities transport over 19,000 passengers to various events downtown, with more that half of those (approximately 13,000) coming from their Crossroads facility located within the ICM Corridor.

Figure 20. Timeline for Fiesta Event. Source: Texas Department of Transportation

3.5 Severe Ice Storm Scenario

This scenario involves a severe ice storm affecting the majority, if not all, expressways in San Antonio. The safe travel of motorists on the expressways is significantly impacted in San Antonio during an ice storm due the number of bridges, fly-over intersections, and split-level elevated expressway sections located around downtown. In addition, due to San Antonio’s typically warm climate, limited deicing infrastructure is available. During an ice storm scenario, the decisions to close or open parts of the expressway are made by a committee consisting of the TxDOT District Maintenance Engineer, an SAPD Lieutenant (or highest officer that is available), and the TxDOT Traffic Operations Director. This group forms the ice plan committee that is responsible for ensuring safe travel during the ice event. These decisions are then passed down to the appropriate organizations for execution. Initially, only the bridges and highest sections of the expressway are closed, but if necessary, any and all of the expressways may be closed until they are believed to be safe for travel. Figure 21 shows a timeline for the severe ice storm scenario.

Figure 21. Timeline for Severe Ice Storm. Source: Texas Department of Transportation

3.6 Evacuation Scenario

At 1:00 PM on a weekday a tanker truck carrying hydrochloric acid crashes on IH 10 East between Wurzbach Rd. and Huebner Rd. As a result, an evacuation of a one mile radius surrounding the area is issued by the EOC. During an evacuation event, the EOC is in charge of making all evacuation-related decisions, and the other stakeholder organizations will provide support as needed

The evacuation will be in effect for a minimum of twelve hours as the expressway and surrounding businesses and residential area are cleared. During this time, IH 10 in both directions will be closed one mile from the incident scene. In addition, the surrounding arterials within the one mile radius from the incident will be closed. The USAA campus will also need to be evacuated. USAA has an existing emergency evacuation plan that will be used in conjunction with the EOC evacuation strategy.

As well as being covered by local news, information about the evacuation area will be posted on TransGuide’s, CoSA’s, and VIA’s websites, as well as messages on DMS entering the evacuation area on IH 10, Loop 410, and Loop 1604.

Figure 22. Timeline for Evacuation Scenario. Source: Texas Department of Transportation

4.0 NOTES

None

APPENDIX A

ACRONYMS