1          INTRODUCTION

1.1              BACKGROUND

This Report is the Executive Summary for the independent technical evaluation of the Oregon Green Light CVO project.  The Oregon Department of Transportation (ODOT) is near completion of the implementation of their Intelligent Vehicle Highway System Strategic Plan for Commercial Vehicle Operations (now referred to as ITS/CVO).  Through Green Light, Oregon has installed twenty-one mainline  systems featuring weigh-in-motion (WIM) devices and automatic vehicle identification (AVI) at the major weigh stations and ports-of-entry in the state.  In addition, certain sites have been equipped with safety enhancements that regulate road conditions and speed. Examples are the Downhill Speed Information System at Emigrant Hill, and the installation of weather stations at three other locations.

The purpose of this report is to present a summary of the findings of all the Detailed Test Plans conducted for the evaluation.  The Detailed Test Plans were published in 1997, ”The Oregon ‘Green Light’ CVO Evaluation -Detailed Test Plans” [1].  Earlier documents providing essential background to the Evaluation are the Evaluation Plan [2], and, Individual Test Plans (ITP) [3].

Each of the tests conducted by the research team for the evaluation of Green Light addressed one of five goals of the evaluation as documented in the Evaluation Plan [2].  These are:

·         Assessment of Safety

·         Assessment of Productivity

·         Assessment of User Acceptance

·         Assessment of Mainstreaming Issues

·         Assessment of Non-Technical Interoperability Issues

 

The objectives associated with each goal are given in detail in The Oregon “Green Light” CVO Project - Individual Test Plans (ITP) [3].    The detailed test plan documents [1] expand on the information provided in the ITP and provide in detail the activities planned for each evaluation measure.

 

1.2              PURPOSE AND SCOPE

The purpose of this Executive summary is to summarize the principal findings from each Detailed Test Plan (DTP).  Each of the DTP’s is summarized in Exhibit 1-1.

As the evaluation progressed, some simplifications were made as it became clear that some elements of Green Light would be modified or eliminated. For example, objective 2.6 was eliminated because vision technology was eliminated from ODOT’s plans.  Also, a major change was implemented for DTP #7 where a simulation tool was developed to enable benefits of electronic screening to be evaluated. Simulation was necessary because the evaluation was proceeding concurrently with deployment, and, it was not possible to collect data that would enable measurement of impacts. Because the impact of pre-screening on fuel consumption was also determined using the simulation, that study (DTP #9) is reported with DTP #7. Exhibit 1-2 shows a summary of the DTP’s that were completed.

 

The findings will be presented in Chapter 2, in the order of the detailed test plans. A general discussion regarding the success of the Green Light project is given in Chapter 4. Conclusions and Recommendations are given in Chapter 4.

EXHIBIT 1-1 Summary of Detailed Test Plans as Planned

 

 

 

 

EXHIBIT 1-2   Summary of DTP’s as Completed

 

2        SUMMARY OF FINDINGS

 

This chapter summarizes the findings from each of the detailed test plans.

 

 

2.1              DTP #1 – Inspection Compliance

 

Out-of-service violations found during a series of random inspections (in 1998 and 1999) were used as an indicator of change in vehicle safety. The study found no significant changes in compliance rates at sites where Green Light  technology was deployed.  However, there was a significant increase in the total number of violations per inspection at non-GL, fixed sites. The most consistent pattern observed was a decrease in violation rates at non-fixed (or mobile) sites.  The number of violations, the number of OOS violations, and the number of vehicle OOS violations per inspection decreased.  Combining data across site types, the only significant difference was an increase in violations per inspection between 1998 and 1999.

 

It is important to note that over the course of the evaluation period, from January 1998 to July 1999, there was a low transponder penetration in relation to the total traffic bypassing the Green Light facility at Woodburn POE.  At the end of the data collection period for this study in July 1999 there were approximately 3000 transponders in the field, less than the amount needed to actually show a change in compliance as a result of Green Light.  This number increased substantially to over 10, 000 transponders in the field in July 2000.  Green Light bypasses also increased dramatically from about 28,000 in July 1999 to approximately 60,000 by July 2000.

 

This study established a baseline for future studies that should show that safety compliance increases as Green Light is fully deployed and a significant truck population carry transponders. It is strongly recommended that ODOT conduct random inspections annually so that it can be clearly demonstrated that safety of the truck fleet is Improving.

 

2.2              DTP #2 – Road Weather Information System – Speed Study

 

ODOT’s travel advisory web page has underwent several upgrades in during the last 12 months of the evaluation. In January of 2000, a test version of TripCheck was launched, a high-powered web interface that brings together several mediums of information for travelers.   Information from the Green Light RWIS sensors are combined with 13 other weather stations across the state to provide timely weather and road conditions to motorists. In addition, TripCheck offers general information such as a listing of construction projects that could pose delays, public transportation services and schedules, rest area locations, and scenic byways.

 

The RWIS installations were successful in meeting the goal of providing real-time weather data for public use through the Traffic Management Operations Center in Portland.  The server installations in La Grande, The Dalles and Ashland relay the information quickly and efficiently, enhancing the existing infrastructure used to provide weather conditions in these three areas known for their high occurrence of truck crashes.

 

The interface with truck traffic through the use of variable message signs was not accomplished before the evaluation was completed, due to the incompatibility of the existing hardware interfacing with the signs in Ladd Canyon.  Combined with the prohibitive costs of retrofitting signs with compatible hardware and/or purchasing new signs, this led to an incomplete evaluation of the motor carriers adjusting speed to adverse weather conditions.

 

Detailed test plan #11, the Motor Carrier Survey, provides additional insight into how motor carriers feel about the RWIS system as intended by ODOT.  The survey found that 60% of carriers agree that RWIS would benefit their company (14% disagree and 26% have no opinion).

 

Recommendations for future work would be to pursue the dissemination of real time data to the roadside, rather than solely through the Internet.  With the advent of wireless data communications, trucks could be equipped with palmtop computers that can query road conditions via the Internet. Until such technology is mainstream, information kiosks at rest areas, truck stops, and weigh stations, could be incorporated into ODOT’s existing infrastructure without a great deal of capital expense, and would reach all carriers, regardless of their technological advancements.

 

 

2.3              DTP #3 – Road Weather Information System – Accident Study

 

Available accident data has given a good baseline approach to continued monitoring of accidents in the Ladd Canyon area. It is strongly recommended that ODOT continue to collect data so that the impact of the RWIS can be measured.

 

2.4              DTP #4 – Downhill Speed Information System – Speed Study

 

Although the Emigrant Hill DSIS was not been deployed, the evaluation indicates that DSIS is a valuable tool that will be beneficial to the trucking community.  Emigrant Hill continues to be listed as a high truck crash corridor in the state of Oregon, with 62 crashes occurring in 1999 due to speed and improper overtaking. The DSIS could aid in reducing these numbers through a warning system of advised speeds and personalized signing as proposed in the Green Light Project.

 

OSU recommends that ODOT continue to pursue deployment of this technology, and if possible, conduct an evaluation of its effectiveness.

 

 

2.5              DTP #5 - Downhill Speed Information System – Accident Study

 

Available accident data has given a good baseline approach to continued monitoring of accidents at Emigrant Hill. It is strongly recommended that ODOT continue to collect data so that the impact of the DSIS can be measured.

 

 

2.6              DTP #6 – Tax Collection and Auditing

 

The impact of Green Light increases the capacity of a weigh station to observe motor carriers’ operations. For each truck that uses a transponder, a space is created in the weigh station queue.  Assuming that the ODOT maintains the volume of traffic currently processed through the static scales, the total number of observations will increase equal to the rate of growth in transponder-equipped trucks.  For trucks that have transponders, observations will be recorded at every pass by the weigh station.  For trucks without transponders, the likelihood of having to stop at the static scale, thus being observed will increase.

 

Observations or third party data are an integral part of the weight-mile tax auditing process.  Weight-mile tax reports are generated by the motor carrier on a monthly or quarterly basis.  Reported trips are compared to observations within the state.  Observations are currently made at the weigh station through vehicle weighing, safety inspections, and traffic citations.  Weigh station observations are by far the most prevalent observations. 

 

The increase in the number of observations enabled by Green Light will allow the audit unit to more effectively select motor carriers for audit. By having more observations, there is a greater chance of detecting unreported trips.  Additional observations will also improve the accuracy of motor carrier audits.  The additional information will allow the field auditors to more precisely and assuredly estimate a vehicle’s pattern of operation with the boundaries of Oregon.  This will also serve as a deterrent to weight-mile tax evasion.