Abstract: DynaMIT is a simulation-based real-time system designed to estimate the current state of a transportation network, predict future traffic conditions, and provide consistent and unbiased information to travelers. To perform these tasks, efficient simulators have been designed to explicitly capture the interactions between transportation demand and supply. The demand reflects both the OD flow patterns and the combination of all the individual decisions of travelers while the supply reflects the transportation network in terms of infrastructure, traffic flow and traffic control. This paper describes the design and specification of these simulators, and discusses their interactions.

Abstract: Advanced Parking Management Systems use variable message signs to provide drivers with up-to-date information on the number of open spaces at selected parking lots throughout a city. Drivers passing a variable message sign must decide in which lot to park. Currently, it is not known what fraction will divert to each of the possible lots. This fraction is important to know, because it determines how large an affect an Advanced Parking Management System will have on traffic congestion. In this article, we report two experiments designed to test alternative models of drivers' parking decisions. Both experiments use an advanced driving simulator. This simulator makes it possible to approximate the load that drivers actually experience on the roadway so as get to a more realistic assessment of the strategies employed. Previous research had indicated that drivers use some variation of expected utility theory to select among lots. We find instead that most drivers use a lexicographic decision strategy. Such a strategy greatly reduces the cognitive load on the driver.

Abstract: The number of VMS signs on English motorways has increased substantially in the last few years. Many of these can display text messages and can be used for a number of different purposes. They can, for example, give warning of hazards with greater detail than previously possible, or display a congestion warning that offers drivers the opportunity to choose an alternative route. In principle, non-traffic messages unrelated to immediate traffic conditions can be used to give information about future road works or safety messages, either general or related to particular campaigns. Evidence concerning driver attitudes to non-traffic messages on VMS, indicates that a large number of drivers are in favour of the wider use of safety-related non-traffic messages on VMS. Traffic data indicate that these messages are likely to have some effect on driving behaviour, at least in the short term. A study investigating the effect of VMS message format and content on the efficiency of message recall found that there was little effect on recall ability when information was presented in different orders. The effect on recall of adding extra information was investigated and also the information content of delay / journey time messages. A subsequent investigation was designed to measure the effect of displaying various types of VMS message on the speed and accuracy of route choice decisions. Three types of message were used: non-traffic, tactical and strategic. The presence of contradictory messages on VMS was also investigated. A further study measured the time to locate a target destination and the accuracy of a navigation decision for eight different sign-sequence combinations of VMS and ADS. These included VMS mounted on gantries with ADS, verge-mounted as opposed to gantry-mounted VMS, and sequences with only one BMS. The final study looked at three of the eight sign sequences and used the main TRL Advanced Driving Simulator. The effect on driving behaviour as well as response time and accuracy was measured. (A)

Abstract: Electronic Variable Messages Signs (VMS) are becoming a common fixture along the motorway landscape. They have been implemented at key locations on major roads to warn motorists of traffic incidents and upcoming special events, and to promote roadside safety. VMS technology is similar throughout the world, but the messages displayed (and how the drivers interpret the information) can vary from city to city and from country to country. The purpose of this paper is to compare and contrast motorist perceptions of VMS effectiveness in Canada and the United Kingdom. The general results on motorist attitudes towards potential use of VMS are also presented. The study is based on VMS evaluation around two major cities in the developed world - Toronto, Canada and Manchester, UK.(A)

Abstract: The development of intelligent transport systems (ITS) in South Africa is discussed. The National ITS initiative has objectives relating to advanced public transport systems, electronic toll collection, electronic licensing systems, automatic vehicle location, commercial vehicle operations, advanced traffic management systems and advanced vehicle control systems. Current ITS activities in Gauteng in the Johannesburg/Pretoria corridor are described. Advanced traffic management systems operating or planned for Gauteng include variable message signs, red-light enforcement, traffic monitoring and incident detection, CCTV traffic monitoring, weigh in motion and overload detection, and traffic information reporting. Government policy and legislation relating to ITS is discussed.

Abstract: The expected benefits of varying combinations of intelligent transportation system applications, such as freeway service patrol, changeable message signs, and ramp metering, were examined. The research analyzed the simulated results of a stylized network in a microscopic traffic simulator. The traffic network included parallel roadways, ramp meters, and changeable message signs. These technologies were tested in various combinations. The effectivenesses were determined, and a measure of inter-technology economies was defined. In brief, additional technologies were found to be subadditive, and more benefits came from each technology in isolation than from the bundling of each with other technologies.

Abstract: Arrow panels, consisting of a matrix of lights, symbolically convey additional warning to motorists. Nondirectional arrow panel displays are designated as caution displays. Before 2001, literature lacked significant statistical support for any one type of caution display. A 2001 Oregon Department of Transportation (ODOT) study suggests that the Dancing Diamonds display performs in the field as well as, if not better than, other caution displays. ODOT also found that local citizens preferred the Dancing Diamonds over other caution displays. However, additional research was needed to confirm these findings. The Utah Department of Transportation (UDOT) has used the Dancing Diamonds display since June 1972. To evaluate the effectiveness of the Dancing Diamonds and Flashing Box displays a field experiment was conducted. The results of this experiment show that the Dancing Diamonds was associated with a statistically significant 3 kph (2 mph) reduction in mean speeds, whereas the Flashing Box display was associated with no statistically significant reduction in mean speeds, indicating indicates that the Dancing Diamonds prompts safety near highway work than the Flashing Box. A comprehension/opinion survey was also conducted. Regardless of caution display type, most of the 412 respondents would “slow down” upon seeing any caution display, and they understood the meaning of the display to be “use caution ahead.” Fifty-four percent of drivers thought that use of the Dancing Diamonds would best prompt safe driving, followed by the Flashing Diamonds (43%) and the Flashing Box (3%). For getting attention, 94% said the Flashing Box was the least effective. TRB 2003 Annual Meeting CD-ROM Paper revised from original submittal. B. M. Turley, M. Saito, S. Sherman 2 DANCING DIAMONDS IN HIGHWAY WORK ZONES: AN EVALUATION OF ARROW PANEL CAUTION DISPLAYS INTRODUCTION Arrow panels have been widely used in highway work zones for the past twenty-five years. These panels are signs consisting of a matrix of lights that convey additional warning and direction symbolically to motorists. This matrix of lights is capable of flashing directional displays as well as nondirectional displays. Directional displays, such as “Flashing Arrow” and “Sequential Chevron,” have been effectively used to aid drivers in switching lanes. Directional guidance is the main purpose of arrow panels. However, to maximize safety per dollar of investment, a nondirectional “caution” display has also been used. This caution display is the only nondirectional arrow panel display authorized by the current Manual on Uniform Traffic Control Devices (MUTCD) and is designated “Flashing Caution” (1). The purpose of the caution display is to increase safety near highway work. Caution displays provide additional warning to drivers, so that they may exercise caution while traveling through an upcoming work zone. Safely slowing down, switching lanes on a multilane highway, and being more alert are all acceptable forms of exercising caution. The caution display is currently designated for shoulder work operations and lane closures on a two-lane, two-way highway (1). Unlike all other arrow panel displays, the caution mode never requires the driver to make a lane change. Even when used at a temporarily closed lane of a two-lane, two-way highway, the caution display is meant only to alert the driver and to call attention to the other traffic-control devices. Figure 1 shows the various caution display types. Before the MUTCD 2000 edition, the Flashing Box and Bar were suggested, but any “caution mode consist[ing] of four or more lamps” which “did not indicate a direction” was permitted (2). The Flashing Box and Bar have been used throughout the United States. The Dancing Diamonds pattern has been used in the western states, such as Utah and Oregon. The Utah Department of Transportation (UDOT) has used the Dancing Diamonds display since June 1972 on state funded projects. The Alternating TwoCorner display has been studied in the past, but to the authors’ knowledge has not been used. The Flashing Diamonds pattern was proposed recently by the Utah Department of Transportation (UDOT). The main purpose of this research is to evaluate the effectiveness of the Dancing Diamonds caution display as compared with the standard Flashing Box caution display. A brief literature review was first performed. Second, a field experiment was conducted to gather actual driver responses to caution displays. Third, a TRB 2003 Annual Meeting CD-ROM Paper revised from original submittal. B. M. Turley, M. Saito, S. Sherman 3 comprehension/opinion survey was conducted to measure driver comprehension of caution displays as well as gather opinions concerning caution displays. At UDOT’s request, consideration for the Flashing Diamonds was added midway through this research and, consequently, is analyzed in the comprehension/opinion survey only. These three areas of research are discussed in the paper. The study yielded the following conclusions: (1) there was insufficient past research on which to base caution displays standards; (2) the Dancing Diamonds display was associated with cautious driving, whereas the Flashing Box display seems to have little effect on drivers; (3) there was little difference in driver comprehension between the Dancing Diamonds, Flashing Diamonds, and Flashing Box displays; however, a majority of respondents felt that the Dancing Diamonds display best prompted safety near highway work. LITERATURE REVIEW Non-directional caution displays have not been studied exclusively until recently. This review first focuses on past research, which is the foundation for current standards. In past research, caution displays were appendages to broader research on directional displays. Consequently, only the caution display segments of that research were examined. Second, this review looked at recent Oregon Department of Transportation (ODOT) research (3), which focuses specifically on caution displays. ODOT’s research and evidence suggested that some caution display types were more effective than others. Past Research A December 1978 Federal Highway Administration (FHWA) report consists of two separate studies: a human factors study and a field study (4). This study is accompanied by a set of recommendations.

Abstract: The European VMS Platform has been set up to address issues related to the Trans European Road Network (TERN) and members include the National Road Administrators and Highway Authorities from a number of European Countries. Within Europe a number of projects are currently being undertaken which use VMS to address cross boundary issues. The use of VMS as a tool for disseminating information is therefore expanding with installation programs in a number of countries. This paper gives a brief overview of the European VMS Platform and discusses the approach taken to harmonize VMS related issues across Europe. Furthermore the paper discusses the methods used by the platform, the results of the discussions and covers issues where harmonization is moving forward. Areas where harmonization can only be achieved by allowing a range of options are also being identified. Member countries are writing a series of position papers outlining the policies and practices relating to Variable Message Signs in their respective countries. This paper discusses some of the salient points from these papers, however more complete results will be presented at the conference.

Abstract: Courtesy travel speed advisory systems are used in most states of Australia with some evidence suggesting reduced vehicle speeds are a result. The current review of the literature has primarily shown positive aspects of the systems including: 1. reduction in speeds without the use of engineering interventions; 2. speed reductions without hampering service vehicles; 3. technology allowing the use of courtesy travel speed advice and messages in other situations (for example lane closed), and systems that can be fully portable or fixed as gantries on major arterials and freeways. There tends to be agreement from most Australian state road authorities that the use of courtesy travel speed advisory systems should be owned and operated by personnel other than police. This then frees them up for more important work. However, the perception of 'government revenue raising' activities can be diminished by promoting police operation of non-prosecution activities associated with these systems. A model is suggested for use of the courtesy travel speed advisory systems in the short-term and for permanent installations. (a) For the covering entry of this conference, please see ITRD abstract no. E209619.

Abstract: The provision of parking spaces and guiding traffic to available spaces is becoming a top priority for traffic managers. The SIPARK guidance system from Siemens AG is described. The system is based on the use of Bero ultrasonic sensors for monitoring individual parking spaces. Once a driver has passed the entrance barrier in a car park, the system guides him to a free parking space along the shortest possible route using a system of green arrows. The system has a modular design and uses standardised industrial products based on standards such as the Simatic, the AS-Interface and the Profibus. A PC serves as the car park control centre. The control centre allows visualisation of the whole parking location. The system keeps constant track of the current occupancy status.

Abstract: A traffic light control system comprises a micro processor located at a crossroads connected to a digital subscriber loop and by a broadband network to a central control station. The microprocessor is connected to a traffic light controller, a traffic flow detector and a video camera with compression circuitry. In use the microprocessor receives traffic information from the video camera and traffic flow detector over the DSL which is then transmitted to the central station over a broadband link. The central station calculates the best timing pattern for the traffic lights which are transmitted to the microprocessor and forwarded to the traffic light controller. An electronic display or variable message sign is also be connected to the micro processor to display traffic or public information to drivers.

Abstract: This article describes how a simulation-based evaluation methodology was applied on a variable speed limit signs (VSLS) system designed for a heavily-traveled roadway around Lausanne, Switzerland. Using the MITSIM Laboratory, the evaluation focused on determining the impacts that variable speed limit signs would have on capacity, traffic flow and user safety. In evaluating the efficacy of the VSLS on capacity and congestion, no clear improvement in performance was shown. In terms of the impact on user safety, it was found that a decrease in speed limits for high flow levels and congestion near an intersection led to an increase in safety. However, simulations showed that in the case of an accident which greatly reduced roadway capacity, VSLS did not seem to improve network performance.