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Effect of Variable-Message Signs in Reducing Railroad Crossing Impacts

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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 is evaluated by investigating the use of variable message signs to divert exiting freeway traffic through non-congested alternate exits. This is done using the crossing near the Fredericksburg Rd. exit on I-10 in San Antonio, Texas, as a case study. In the evaluation, microscopic simulation is used to determine the impacts of train operations at the crossing and the potential benefits of a VMS system installed on I-10. These effects are 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 are 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.
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... The effect of VMS in improving the safety and operational efficiency of railroad crossings near I-10 was studied in San Antonio, TX (Sivanandan et al., 2003). Network microsimulation was conducted to evaluate the effectiveness of the proposed VMS suggesting the use of nearby exits to avoid the exit with the railroad crossing and associated congestion. ...
Technical Report
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There is limited research on the effects of variable message sign (VMS) message content on revealed driver behavior. This study investigated the associations of message content with diversion rate during crash incidents using 5 years of VMS message history within a section of I-15 in the state of Utah. The diversion rate was found to be higher when the message consisted of information such as miles to crash, “crash ahead,” location of the crash, delay information, traffic ahead (i.e., is slowing or slows), and lane of the crash. However, “use caution,” speed suggestions, and “prepare to stop” content were found to be negatively associated with diversion rate. When considering message content combinations, combinations of miles to crash + “prepare to stop” had the highest diversion rate, followed by combinations of crash location + delay information, and miles to crash + “use caution” + lane of crash information. These findings could be used by agencies to make informed decisions about choosing the message content during future crash incidents. The study also revealed that a higher diversion rate is associated with a shorter distance between the crash location and VMS device location, which suggests recommending increasing the number of VMS devices, particularly in crash-prone areas. In addition, the diversion rate correlated with some roadway characteristics (e.g., occupancy in mainline) along with the temporal variations.
... Pulugurtha and Desai [15] compared the capabilities of Synchro and VISSIM in modelling at-grade railroad crossings and discussed the versatility of both the software. Sivanandan et al. [16] concentrated mainly on at-grade railroad crossings located at freeway exits. A potential solution for this type of at-grade railroad crossings is the use of variable message signs. ...
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This paper focuses on modeling and evaluating the effect of detector placement (distance), train, and traffic characteristics on operational performance of at-grade railroad crossings. Train and vehicular traffic related data were collected at an at-grade railroad crossing in the city of Charlotte, NC, USA. The collected data was then loaded into VISSIM traffic simulation software to develop a calibrated model and compute operational performance measures such as delay, the number of stops, and queue length. In addition, VISSIM traffic simulation software has an essential tool to place the detector on the track within a certain distance from the road. This tool was used to compute operational performance measures by detector placement (distance from the road). The results obtained by detector placement, the length of the train, speed of the train, and traffic volume are summarized. The findings help engineers and practitioners to place detectors on the track, within an ideal distance, for reducing delay and congestion without compromising on safety and flow of the traffic passing an at-grade railroad crossing.
... For efficient DTA control, DTA algorithms should be able to sufficiently capture and consider them. Examples of current literature include the works of Ran and Boyce [200], Peeta et al. [174], Ziliaskopoulos and Waller [262], Dion and Rakha [72], Sivananden et al. [223], Rakha et al. [190,191], Rakha and Zhang [197]. ...
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