2.1 Arterial Management Systems

Arterial management systems manage traffic along arterial roadways, employing traffic detectors, traffic signals, and various means of communicating information to travelers. These systems make use of information collected by traffic surveillance devices to smooth the flow of traffic along travel corridors. They also disseminate important information about travel conditions to travelers via technologies such as dynamic message signs (DMS) or highway advisory radio (HAR).

Figure 2.1.1, showing a portion of the ITS classification scheme, lists the variety of systems that may be employed as part of arterial management systems. Many of the services possible through arterial management systems are enabled by traffic surveillance technologies, such as sensors or cameras monitoring traffic flow. These same sensors may also be used to monitor critical transportation infrastructure for security purposes.

Traffic signal control systems address a number of objectives, primarily improving traffic flow and safety. Transit signal priority systems can ease the travel of buses or light-rail vehicles traveling arterial corridors and improve on-time performance. Signal preemption for emergency vehicles enhances the safety of emergency responders, reducing the likelihood of crashes while improving response times. Adaptive signal control systems coordinate control of traffic signals, across metropolitan areas, adjusting the lengths of signal phases based on prevailing traffic conditions. Advanced signal systems include coordinated signal operations across neighboring jurisdictions, as well as centralized control of traffic signals, which may include some necessary technologies for the later development of adaptive signal control. Pedestrian detectors, specialized signal heads, and bicycle-actuated signals can improve the safety of all road users at signalized intersections. Arterial management systems can also apply unique operating schemes for traffic signals, portable or dedicated dynamic message signs, and other ITS components to smooth traffic flow during special events.

A variety of techniques are available to manage the travel lanes available on arterial roadways, and ITS applications can support many of these strategies. Examples include dynamic posting of high-occupancy vehicle (HOV) restrictions and the use of reversible flow lanes, allowing more lanes of travel in the peak direction of travel during rush hours. Parking management systems, most commonly deployed in urban centers or at modal transfer points such as airports, monitor the availability of parking and disseminate the information to drivers, reducing traveler frustration and congestion associated with searching for parking. Organizations operating ITS can share information collected by arterial management systems with road users through technologies within the arterial network, such as dynamic message signs or highway advisory radio. Arterial management systems may also include automated enforcement programs that increase compliance with speed limits, traffic signals, and other traffic control devices.

Sharing information with other components of the ITS infrastructure can also have a positive impact on the operation of the transportation system. Examples include coordinating operations with a freeway management system or providing arterial information to a traveler information system covering multiple roadway and public transit facilities.

Table 2.1.1 provides information on the benefits and costs of arterial management systems. An assessment of the impact of these systems is indicated by using the symbols in the Impact Legend at the bottom of each page.

Table 2.1.1 – Benefits and Costs of Arterial Management Systems

Surveillance

Benefits
Supporting role, no benefits information.
Costs
Unit Costs Database	Roadside Telecommunication subsystem Roadside Detection subsystem Transportation Management Center subsystem	See Appendix A
(New) System Cost	The Utah Advanced Transportation Management System (ATMS) includes more than 230 cameras to observe incidents and congested areas. Camera coverage is primarily on freeways and grade-separated facilities; however, there are some deployments at key intersections on surface streets. The capital cost of the cameras includes the cameras and installation. The lifetime of the cameras is 10 years.[3]	Cameras and installation cost: $8.4 million Annual operating cost for cameras: $75,600
(New) System Cost	In April 2001, the city of Colorado Springs, Colorado, began the process of replacing in-pavement loops with video detection at 420 intersections. Separate contracts were let for equipment and installation. The equipment included a two-year warranty and free upgrades. (Fine-tuning of the cameras was performed by city crews.) The cost per intersection varied based on the type of intersection (mast arm, span wire), number of cameras (one to eight), and additional work (lighting). The average cost per intersection does not include city crew staff time, but does include the cost of a custom-built video van, an additional bucket truck, and various test equipment. The relatively low cost per intersection is due in part to the large number of intersections involved in the project.[40]	Average cost per intersection: $13,000 Total project cost: $5.6 million

Traffic Control: Transit Signal Priority

Benefits
Goal Area	# of Studies	Impact	Example
Mobility	15	++	Experience in 11 cities in the U.S. and abroad show 2–20% to 20% improvement in bus travel time.[12, 41, 42, 43, 44, 45, 46] Several studies show significant reduction in travel time variability, with a corresponding improvement in on-time performance.
Productivity	2	+	On a Toronto, Canada, light-rail transit line, signal priority allowed same level of service with less rolling stock.[47]
(New) Energy/ Environment	2	+	Simulation of a hypothetical transit signal priority system along a heavily traveled corridor in Arlington County, Virginia, found a 2–3% reduction in fuel consumed by buses across a number of priority scenarios.[42]
Costs
Unit Costs Database	Roadside Telecommunications subsystem Roadside Control subsystem Transit Management Center subsystem Transit Vehicle On-Board subsystem Transportation Management Center subsystem		See Appendix A
(New) System Cost	A bus rapid transit (BRT) system was deployed to enhance bus operations and improve customer service in the Greater Vancouver area of British Columbia, Canada. In August 2001, BRT route #98 B-Line was introduced to connect the city of Richmond with Vancouver. The BRT service includes several ITS components, including automated vehicle location (AVL) technology, transit signal priority systems, on-board voice and digital announcements of next stop information, and real-time bus arrival time information using digital countdown signs at bus stops.[48]		Transit signal priority system: $1.6M (CAD) (2001)
System Cost	The Los Angeles DOT (LADOT) implemented a $10 million bus signal priority demonstration project along two corridors (Ventura Boulevard and the Santa Monica-Beverly Hills-Montebello route) in the City of Los Angeles, California. The initial deployment began in June 2000. The system consists of 331 loop detectors, 210 intersections equipped with automatic vehicle identification (AVI) sensors at the controller cabinet, and 150 transponder-equipped buses. Loop detection technology is used to detect the presence of a bus approaching the intersection. The bus identification is detected by the AVI sensor and sent to the transit management computer located at the LADOT transportation management center. The system checks the bus' schedule and headway to determine if it is early or on time. If the bus is behind schedule, one of four types of priority modes is granted.[46, 49]		Total project cost: $10 Million Average cost: $13,500 per signalized intersection (2000) Transponder cost: Approximately $75 per bus (2000)
System Cost	The cost of transit signal priority systems varies based on many factors such as system design and functionality and type of equipment. Based on information reported in a recent ITS America report, the per-intersection cost of a transit priority system covers a wide range.[50]		Cost range: $8,000–$35,000 per intersection

Traffic Control: Emergency Vehicle Preemption

Benefits
Goal Area	# of Studies	Impact	Example
(New) Mobility	3	++	A study in Houston, Texas, found signal preemption reduced average emergency vehicle response times by 16% in one fire district, 23% in another.[51] A simulation study in the Virginia suburbs of Washington, D.C., found emergency vehicle preemption caused minimal increases in average travel times (2.4%) for all traffic.[52]
Costs
Unit Costs Database	Roadside Telecommunications subsystem Roadside Control subsystem Emergency Response Center subsystem Emergency Vehicle On-Board subsystem Transportation Management Center subsystem		See Appendix A
System Cost	Several intersections in British Columbia, Canada, were equipped for emergency vehicle preemption. The siren of an emergency vehicle is detected and initiates a green signal for the oncoming vehicle. Pedestrian crossing signals are switched to DON'T WALK. A visual verification system (set of blue and white lights) indicates that the intersection is controlled by an emergency vehicle preemption system and when the system has been activated.[53]		Cost: $4,000 per intersection (can be less if multiple intersections are equipped)

Traffic Control: Adaptive Signal Control

Benefits
Goal Area	# of Studies	Impact	Example
Mobility	18	++	Studies from six cities in Canada, Brazil, Spain, and Scotland indicated delay reductions from 5–42% after installation of adaptive signal control.[54, 55, 56, 57, 58]
(New) Capacity/ Throughput	1	+	A study of the integrated deployment of freeway ramp metering and adaptive signal control on adjacent arterial routes in Glasgow, Scotland, found a 20% increase in vehicle throughput on the arterials and a 6% increase on freeways. Arterial traffic increased 13% after implementation of ramp metering and an additional 7% with the initiation of adaptive signal control.[58]
Energy/ Environment	3	+	Adaptive signal control in Toronto, Canada, has yielded emission reductions of 3–6% and fuel savings of 4–7%.[57]
Costs
Unit Costs Database	Roadside Telecommunications subsystem Roadside Detection subsystem Roadside Control subsystem Transportation Management Center subsystem		See Appendix A
System Cost	Arlington County, Virginia, Department of Public Works, Traffic Engineering Division, recently brought 65 intersections (expandable to 235) under an adaptive signal control system. The cost included software, hardware, roadside equipment, cabling, mobilization and maintenance of traffic, installation, training, maintenance and test equipment, and system documentation.[59]		Total project cost: $2.43 million (2001)

Traffic Control: Advanced Signal Systems

Benefits
Goal Area	# of Studies	Impact	Example
Safety	3	+	Signal coordination along a Phoenix, Arizona, corridor resulted in a 6.7% reduction in crash risk, calculated based on improved travel speeds and a reduction in the average number of stops.[60]
(New) Mobility	16	++	Signal coordination at 145 intersections in Syracuse, New York, reduced the total delay experienced by vehicles during the a.m.-peak, mid-day, and p.m.-peak periods by 14–19%.[1]
(New) Capacity/ Throughput	1	?	A simulation study of re-timed traffic signals along two major arterials north of Seattle, Washington, found a 7.0% annualized reduction in vehicle delay, accompanied by a 0.2% increase in vehicles traveling the corridor.[61]
Productivity	3	+	Assigning a monetary value to reductions in delay, fuel use, and emissions achieved during a $4.7 million dollar upgrade of the Richmond, Virginia, signal system yielded benefits of $4.2 million annually.[62]
Energy/ Environment	9	+	Modeling studies of coordinated signal control in five U.S. localities found reductions in fuel use ranging from no significant change in Seattle, Washington, to a 13% decline in Syracuse, New York.[1, 60, 61, 62, 63]
Costs
Unit Costs Database	Roadside Telecommunications subsystem Roadside Detection subsystem Roadside Control subsystem Transportation Management Center subsystem		See Appendix A
(New) System Cost	To improve air quality in downtown Syracuse and Onondaga County, the New York State Department of Transportation (NYSDOT) installed a computerized traffic signal system and optimized the signal timing of 145 intersections.[1]		Total project Cost: $8,316,000
(New) System Cost	The Utah Advanced Transportation Management System (ATMS) includes a coordinated signal system. More than 600 of the 900 signals in the Salt Lake Valley are connected to the traffic operations center (TOC). With the installation of the communication system and central traffic control system, monitoring and adjusting the signal system is performed at the TOC rather than by site visit. Currently, more than 50 coordinated corridors have been implemented by Utah DOT. The cost of the signal system includes only the communication capability. The signals were already in place prior to the ATMS implementation.[3]		Signal communication capability: $2.2 million Annual maintenance cost: $15,000

Traffic Control: Bicycle and Pedestrian

Benefits
Goal Area	# of Studies	Impact	Example
(New) Safety	1	+	Automatic pedestrian detection systems deployed at four intersection crosswalks in three U.S. cities resulted in a 24% increase in the number of pedestrians who began crossing during the WALK signal, and an 81% decrease in the number of pedestrians who began crossing during the steady DON'T WALK signal.[64]
Costs
Unit Costs Database	Roadside Telecommunications subsystem Roadside Detection subsystem Roadside Information subsystem		See Appendix A
System Cost	A downtown Boulder, Colorado, intersection has been equipped with a series of four flashing in-pavement lights per lane. This high pedestrian-volume intersection is also equipped with two flashing pedestrian signs. The lights and signs are activated manually. Project cost includes equipment and installation costs.[53]		Project cost: $8,000–$16,000

Traffic Control: Special Events

Benefits
No data to report.
Costs
(New) Unit Costs Database	Roadside Telecommunications subsystem Roadside Detection subsystem Roadside Control subsystem Roadside Information subsystem Transportation Management Center subsystem	See Appendix A
(New) System Cost	The Utah ATMS includes a coordinated signal system. More than 600 of the 900 signals in the Salt Lake Valley are connected to the TOC. With the installation of the communication system and central traffic control system, monitoring and adjusting the signal system for special events is performed at the TOC. The cost of the signal system includes only the communication capability. The signals were already in place prior to the ATMS implementation.[3]	Signal communication capability: $2.2 million Annual maintenance cost: $15,000

Parking Management

Benefits
Goal Area	# of Studies	Impact	Example
Capacity/ Throughput	1	?	Experience with parking management systems in Europe indicates a 25% reduction in downtown traffic volumes related to the search for parking.[65]
Costs
Unit Costs Database	Roadside Telecommunications subsystem Roadside Information subsystem Parking Management subsystem Transportation Management Center subsystem		See Appendix A
(New) System Cost	The Seattle Center Advanced Parking Information System in Seattle, Washington, provides information and routing directions to three major parking centers via variable message signs. This information is also available via the Internet, phone, and pagers to travelers prior to leaving for an event as well as travelers en route. Detection technology is used to monitor parking availability.[5]		Project cost: $925,265(1998) Annual O&M cost: $50,523(1998)

Information Dissemination: Dynamic Message Signs

Benefits
No data to report (for applications on arterials).
Costs
Unit Costs Database	Roadside Telecommunications subsystem Roadside Information subsystem Transportation Management Center subsystem	See Appendix A
(New) System Cost	The Utah DOT operates and maintains more than 69 permanently mounted variable message signs (VMS) on freeways and surface streets as part of the Utah Advanced Transportation Management System. Portable message signs are also used along roadsides where there is no permanent VMS. The annual operating cost is based on power consumption (electricity).[3]	Cost of VMS: $15.25 million Annual VMS operating cost: $21,960

Information Dissemination: In-Vehicle Systems (IVS)

Benefits
No data to report.
Costs
Unit Costs Database	Vehicle On-Board subsystem	See Appendix A
System Cost	No data to report.

Information Dissemination: Highway Advisory Radio

Benefits
No data to report.
Costs
Unit Costs Database	Roadside Telecommunications subsystem Roadside Information subsystem	See Appendix A
System Cost	No data to report (for applications on arterials).

Enforcement: Speed Enforcement

Benefits
Goal Area	# of Studies	Impact	Example
Safety	5	+	A 1999 Institute of Transportation Engineers (ITE) synthesis study on automated enforcement lists two U.S. cities with automated speed limit enforcement programs, with documented crash reductions of 40% in Paradise Valley, Arizona, and 51% in National City, California.[66]
(New) Customer Satisfaction	1	+	Fifteen months after extensive deployment of automated speed enforcement cameras in Great Britain, a nationwide survey found 70% of those surveyed thought that well-placed cameras were a useful way of reducing accidents and saving lives, while 21% thought that speed cameras were an infringement of civil liberties.[67]
Costs
Unit Costs Database	Roadside Telecommunications subsystem Roadside Detection subsystem Roadside Information subsystem		See Appendix A
(New) System Cost	In April 2000, a cost recovery system for speed and red-light cameras was introduced in eight pilot areas in England, Wales, and Scotland. In Strathclyde, 28 fixed camera sites were established in mostly 30 mph zones. The costs associated with camera enforcement and processing of fixed penalty notices were collected for the first two years. Costs increased for year two, which may be due in part to not all of the sites being fully operational during the first year. In the second half of year two, the number of fixed penalties paid began to plateau, which may be due to increased compliance. In terms of enforcement history, the Strathclyde partnership was one of the more experienced.[67]		First year cost: £204,330 Second year cost: £740,896

Enforcement: Stop/Yield Enforcement

Benefits
Goal Area	# of Studies	Impact	Example
Safety	12	?	Red light camera programs have resulted in reported violation reductions ranging from 20–75%; findings on crash impacts have been inconclusive.[68]
Customer Satisfaction	2	++	Public opinion surveys indicated 60–80% support for red light camera programs.[68]
Costs
Unit Costs Database	Roadside Telecommunications subsystem Roadside Detection subsystem		See Appendix A
System Cost	Red light enforcement cameras have been implemented in numerous cities throughout the U.S. The cost of equipping an intersection for red light enforcement depends on the geometry of the intersection and the number of lanes monitored. Typical implementation costs include camera, poles, loops, wires, and installation. The cost range represents the costs incurred per intersection for the city of Jackson, Michigan, (low-end) and the City of San Francisco, California, (high-end).[69]		Costs per intersection: $67,000–$80,000
(New) System Cost	In April 2000, a cost recovery system for speed and red-light cameras was introduced in eight pilot areas in England, Wales, and Scotland. In Nottingham, two digital camera sites were implemented on its ring road. Mobile enforcement also took place at seven mobile sites and 19 red-light sites. Most enforcement took place in 30 mph zones. The costs associated with camera enforcement and processing of fixed penalty notices were collected for the first two years. Costs increased for year two, which may be due in part to not all of the sites being fully operational during the first year. In the second half of year two, the number of fixed penalties paid began to plateau which may be due to increased compliance. The Nottingham partnership had comparatively less experience of camera enforcement.[67]		First year cost: £622,371 Second year cost: £778,536

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