Use Of Variable Message Signs Research Articles

Safety in Work Zones

The use of variable message signs at road construction sites can help keep workers and drivers safe at all times of the day

Effects of Weather Related Safety Messages on the Motorway Traffic Parameters

Intelligent transport systems have a huge importance during adverse weather conditions. These systems call the drivers’ attention to possible dangers by the use of variable message signs installed along the motorways. Several researchers have dealt with the connection of weather and traffic safety in the last decades, but they have not investigated the effects of weather related messages. This paper examines the impact of weather-related warning messages on traffic in adverse weather circumstances on the Hungarian motorways. Three independent databases were analyzed in order to compare the speed-reducing effect of specific signs during different weather events and precipitate intensities.

Evaluation of the effectiveness of portable variable message signs in work zones in United Arab Emirates

Highway work zones pose a higher risk of crashes due to an increase in the complexity of driving task and driver information. An effective way to impart variable pertinent information to the drivers based on local conditions is the use of variable message signs (VMSs). This study focuses on the effectiveness of portable VMSs (PVMSs) in altering speeds using data obtained during a field deployment, as well as qualitative data from road users and construction workers collected using surveys. Speed, volume, and classification data were collected before and during the installation of the PVMS. A questionnaire was developed related to the PVMS performance, which was used to gauge the perception of drivers and construction workers for the purpose of qualitative analysis. The field data and the survey results were correlated to study the impact of PVMS in reducing the speed of vehicles. The survey results indicated that the drivers as well as the construction workers perceived PVMS to have a positive effect on safety and that PVMS provides reliable information. However, the quantitative analysis of vehicular speeds before and during the installation of PVMS revealed no statistically significant change in speeds.

Assessing the Importance of Vehicle Type for the Implementation of Eco-routing Systems

Nowadays, several methods to promote a more sustainable distribution of traffic flows are available. In response to rising energy costs and increased environmental concerns, eco-friendly route choices can be provided individually by means of smart navigation tools that allow several vehicle routing options designed to minimize air pollutant emissions and fuel consumption. Simultaneously, the use of intelligent road pricing systems and the use of variable message signs can change the route choice process of drivers (and thus network equilibrium), by varying the perceived attributes of competing routes. However, so far too little attention has been paid to the fact that the eco-friendliness of various routes may change, depending on vehicle characteristics which may cause problems on the efficiency of these systems. This issue has been empirically addressed in this research, using a database of more than 13,330km of GPS data in six different Origin-Destination (OD) pairs and 9 different routes. Simultaneously, two different approaches for estimating (CO2, HC, CO, NOX) emissions were tested: a) second-by-second vehicle dynamics, using the Vehicle Specific Power (VSP) instantaneous model; and b) route average speed using the EMEP/EEA methodology. The results show that depending on the characteristics of the routes associated with a certain OD pair, the eco-friendly route may differ according to the vehicle model and the emissions estimation method. Innovative approaches to provide accurate emissions and eco-routing information are needed.

Methodology to Predict Driver Vision Impairment Situations Caused by Sun Glare

This paper presents a methodology to determine the days and times of the year when sun glare may impair drivers’ vision on a particular road section, depending on the geographic location, the geometric design of the road, and the physical characteristics of the environment. The methodology is based on applying cylindrical charts to represent the entire set of variables involved in the problem. The results may be used to study in detail the problem at critical sections of existing or newly designed roads such as intersections, freeway ramps, and tunnel exits. The methodology may also support the use of variable message signs to warn drivers of the risk of vision impairment at the exact times and locations where high-glare conditions occur.

Rhode Island Transportation System in Natural or Human-Caused Disasters

The rapid advance of technology has presented authorities with many new tools that they can use to monitor and control roadways for their safe, efficient, and convenient use by motorists, working toward an intelligent transportation system that adapts to dynamic situations that best serve motorists. Recent natural and human-caused disasters have demonstrated that there are significant challenges yet to be overcome by the advancing technology of transportation systems. A significant problem is a lack of clear, efficient communication during emergencies. The public requires timely information and guidance during and after a catastrophic event. This research investigated the feasibility of enhancing transportation system preparedness by creating messages to aid motorists during natural or human-caused disasters by supplementing the existing message display libraries for variable message signs (VMSs) and dynamic message signs (DMSs). This investigation considered the current transportation emergency communication environment and attempts to enhance communication and preparedness by improving the design and display of messages on VMSs and DMSs. The study examined 465 Rhode Island drivers by using a computer survey and 157 Rhode Island drivers by using driving simulation to research important factors in the design and deployment of message displays. The results indicated that the supplementation of communication through the use of VMSs and DMSs is a viable alternative and that there are design factors that can be used to help develop new and improve existing messages through further testing and implementation.

ITS applications for work zones

AbstractThe use of Intelligent Transportation Systems (ITS) in construction work zones to disseminate traffic information has increased significantly in recent years, mainly with the use of Variable Message Signs (VMS). VMS are used based on the assumption that informed drivers will make better travel decisions, thereby reducing congestion. However, the extent of change in driver behavior is difficult to predict prior to ITS deployment. This difficulty leads to the larger problem of justifying investment in ITS. This article proposes an ITS deployment decision support tool using micro‐simulation. The approach determines the required diversion effectiveness of a work zone ITS deployment using VMS. The methodology was tested using the Glenmore Trail/Elbow Drive/5th Street interchange project (GE5) in Calgary, Canada. The results indicate that the proposed approach will assist agencies in justifying ITS investment by exhibiting the potential resultant societal benefits.

Questionnaire surveys to evaluate user response to variable message signs in an urban network

The use of variable message signs (VMS) to provide traffic information is widespread, but success depends upon behavioural response to the sign messages. The research described here focuses on user acceptance of VMS located in an urban road network (Southampton, UK), and investigates the public's perceived effectiveness and usefulness of these signs through the use of revealed preference questionnaire surveys and travel diaries. Three hundred and sixty-five commuters regularly driving into Southampton from the outskirts of the city completed a travel diary for a 5-day period as well as a general questionnaire, and 660 infrequent travellers to Southampton completed the general questionnaire. The study showed that it is difficult to capture a meaningful sample size of respondents passing an `active' VMS in a real-life incident scenario. Less than 1% of the commuter sample stated that they had diverted to an alternative route during the travel diary week as a result of VMS information, although this did correspond to 53% of those 45 drivers originally intending to travel past the incident location. The results showed that the VMS messages were well-understood and legible, and also indicated that a default VMS message reporting no problems in the network can indirectly affect a driver's route choice.

Investigating Limits of Benefits Provided by Variable Message Signs in Urban Network

A major objective for providing real-time traffic information to drivers is to improve the efficiency of the road network, especially in incident situations. However, the subsequent effects depend on behavioral response, in both interpreting available information and reacting to it. Research focusing on the use of variable message signs (VMSs) was done in the urban network of Southampton, in the United Kingdom, a site chosen because of the innovative large-scale application of an urban VMS system and the availability of traffic data derived from urban traffic controls using the split-cycle offset optimisation technique (SCOOT) and other detectors. Although previous research regarding VMSs located in inter-urban areas such as motorways is well documented, the use of VMSs within urban areas is not widespread. The research analyzed several case studies by using detector data collected during incident scenarios at seven locations to assess driver response to VMS messages in terms of diversion rates. Positive driver responses were measured for all, with diversions ranging from 2% to 30%, although not all were solely attributable to VMS information. No relationships between the severity of VMS message and driver response could be identified. A simulation model was then used to quantify the potential network benefits of traffic information. A main finding was that if the diversionary route had sufficient spare capacity, substantial VMS benefits were potentially attainable, although these benefits were not distributed equally.

Effect of Variable-Message Signs in Reducing Railroad Crossing Impacts

At-grade highway–railroad crossings cause traffic control problems that have a bearing not only on traffic safety but also on traffic flow efficiency. Crossings located near freeway exits pose particularly acute problems, as long closures could result in vehicle queues that spill back onto freeway lanes. A potential solution to this problem was evaluated by investigating the use of variable message signs to divert exiting freeway traffic through non-congested alternate exits. This was done using the crossing near the Fredericksburg Road exit on Interstate 10 (I–10) in San Antonio, Texas, as a case study. In the evaluation, microscopic simulation was used to determine the impacts of train operations at the crossing and the potential benefits of a variable-message sign (VMS) system installed on I–10. These effects were gauged by considering scenarios with varying levels of train duration, traffic demand on the freeway exit, and driver compliance to the displayed messages. While little network improvements were obtained, the analysis demonstrates the capability of the INTEGRATION software in analyzing such scenarios and the extent to which exiting freeway traffic may benefit from the VMS system, as well as the need to consider fuel consumption and vehicles emissions in the evaluations.

Evaluating Networkwide Effects of Variable Message Signs in the Netherlands

The use of variable message signs (VMSs) is generally considered to be a powerful tool to influence route choice so as to increase safety and comfort during driving and improve network performance and to make optimum use of available capacity. Assessing whether such effects actually occur when VMSs are installed is a difficult task. This paper summarizes an extensive evaluation study carried out on the installation of 14 new VMSs on the Amsterdam orbital motorway. The study involves a number of issues. First, a networkwide analysis of aggregate performance indicators, such as traffic performance, severity of congestion, and travel time delay, is included. Second, the relation between the messages displayed on the VMS and the travel times experienced by drivers is analyzed. Finally, a stimulus-response analysis to find out how drivers actually respond to the messages is described. The study showed that the use of VMSs has a positive impact on network performance in the Amsterdam freeway system. Total congestion has decreased, and traffic performance has increased. Variation in congestion has decreased as well as variation in average travel speed. This finding implies that travel time has become more reliable and that the traffic flow is more homogeneous. The technical assessment showed that the displayed queue lengths, if interpreted correctly by drivers, are a good measure for expected delay. User response analysis showed that information has a significant effect on route choice. In general, the VMSs were found to improve the efficiency and reliability of the freeway system.

Traffic Information and Driver Behaviour in Paris Region

The 600 Kilometer freeway network around Paris is operated by a single traffic management and control authority. They develop a program called SIRIUS, the largest urban and peri-urban testbed project for the use of variable message signs in Europe. Half of SIRIUS has been in operation since the end of 1992. Currently, real-time traffic information is provided to drivers via 200 remotely controlled variable message signs. The traffic data are gathered from 5, 000 buried loop detectors. The survey showed that drivers respond to road-side information service and that variable message signs would be an effective tool to influence motorist diversion behavior. Recent new results reveal the quantification of this effect and the potential for the motorist to divert, whether they are accustomed or not to the area.

Matrix signs for motorways: System design and optimum light intensity : Padmos, P., Van den Brink, T.D.J., Alferdinck, J.W.A.M., and Folles, E. In: Vision in Vehicles — II, A.G. Gale, M.H. Freeman, C.M. Haslegrave, P. Smith and S.P. Taylor (Eds). North-Holland, Amsterdam, 1988, pp 269–276, 5 refs.

This paper describes the evaluation of the use of variable message signs (VMS) on Dutch freeways. It was found that although the VMS reduced the number of traffic accidents, that the influence of the VMS on traffic flow was less. Experiments were conducted to determine the optimum light characteristics of the signs. The results led to methods for controlling the intensity of the VMS as a function of ambient light levels.