The likelihood of a crash or potential is significantly affected by the short-term turbulence traffic flow. For this reason, must be estimated on real-time basis monitoring current condition. In regard, probabilistic prediction model relating to various flow characteristics that lead occurrence, “crash precursors,” was developed. development previous model, however, several assumptions were made had not been clearly verified from either theoretical empirical perspectives. Therefore,...

Traffic flow characteristics that lead to crashes on urban freeways are examined. Since these observed prior crash occurrence, they referred as “crash precursors.” The objectives ( a) explore factors contributing changes in rate for individual vehicles traveling over an freeway and b) develop a probabilistic model relating significant precursors potential. data used examine were extracted from 38 loop detector stations 10-km stretch of the Gardiner Expressway Toronto 13-month period. An...

Variable-speed limit sign (VSLS) systems enable transportation managers to dynamically change the posted speed in response prevailing traffic and/or weather conditions. Although VSLSs have been implemented a limited number of jurisdictions throughout world, there is currently very documentation that describes quantitative safety and operational impacts. Furthermore, impacts reported are primarily from Europe may not be directly transferable other such as North America. This paper presents...

Variable speed limit (VSL) systems enable freeway system managers to change the posted on a section of roadway in response varying conditions. VSL goals may include homogenizing traffic flow, improving safety, and/or reducing driver stress. Although it is understood that effectiveness impacted by level compliance, which itself influenced extent enforcement, very little known about strength these impacts. This paper uses simulation model evaluate sensitivity safety and operational impacts...

A method is suggested for evaluating the effectiveness of variable speed limits in reducing freeway crash potential. The real-time prediction model that was developed earlier studies used to estimate potential different control strategies limits. To mimic realistic responses drivers changes limits, a microscopic traffic simulation used. results indicate total over entire segment could be significantly reduced under limit with minimal increase travel time compared fixed limit. methodology...

Summary Bus rapid transit system is designed to provide high‐quality and cost‐efficient passenger transportation services. In order achieve this design objective, effective scheduling strategies are required. This research aims at improving the operation efficiency service quality of a BRT through integrated optimization its headways stop‐skipping strategy. Based on cost analysis for both passengers agencies, an model established. A genetic algorithms based algorithm application‐oriented...

Pedestrian volume at intersections is a key input to transportation processes and vital for developing pedestrian-centric interventions. Though technological solutions provide continuous monitoring of field counts do exist, most jurisdictions not have this technology widely deployed therefore still require means estimating volumes. Conventional estimation methods, such as expansion factor methods or the development direct-demand (DD) models, are alternatives typically employed by...

Jurisdictions need estimates of bicycle activity levels for road safety and infrastructure planning studies. When counts are not available, direct-demand (DD) models can be used to estimate (often as annual average daily [AADB] counts) a function demographic network data. However, all jurisdictions have sufficient count data or resources develop their own DD model would benefit from applying developed in another jurisdiction. there is little prior evidence the spatial transferability...

Delays that individual vehicles may experience at a signalized intersection are usually subject to large variation because of the randomness traffic arrivals and interruption caused by signal controls. Although such have important implications for planning, design, analysis controls, currently no analytical model is available quantify it. The development an predicting variance overall delay described. constructed on basis evolution patterns under two extreme conditions: highly undersaturated...

The use of probe vehicles to provide estimates link travel times has been suggested as a means obtaining within signalized networks for in advanced information systems. Past research the literature provided contradictory conclusions regarding expected accuracy these probe-based estimates, and consequently estimated different levels market penetration required sustain accurate data an traveler system. This paper examines effect sampling bias on estimates. An analytical expression is derived...

Many existing freeway traffic management systems (FTMS) use speed data from loop detectors as input to various functions, such automatic incident detection, and traveler information system components. In many cases, these FTMS include single-loop that are not able measure vehicle speed. Typically, estimates made on the basis of volume, occupancy measurements, average length. Unfortunately, accuracy is generally very poor. This paper presents a method for improving estimates. The proposed...

Automatic vehicle location (AVL) and automatic passenger counting (APC) systems can provide rich archived databases for analysis. Previous work has focused on using AVL–APC data to evaluate system performance various quantitative measures visualization methods. Given the large volume of data, there is a benefit automating creation visualizations “pushing” interesting information users, rather than requiring users create figures sift through them their own. This paper presents methodology...

Transit agencies seeking to improve transit service delivery are increasingly considering the deployment of signal priority (TSP). However, impact TSP on and general traffic stream is a function many factors, including intersection geometry, timings, demands, strategies parameters, vehicle headways, timing when vehicles arrive at intersection, etc. Previous studies have shown that depending these net in terms or person delay can be positive negative. Furthermore, because financial...

This paper evaluates the influence of on-street bike lanes on lateral separation between motor vehicles and cyclists when vehicle overtakes cyclist investigates relationship passing behavior traffic conditions. A bicycle was instrumented with a sensor array that consisted an ultrasonic sensor, GPS receiver, video camera. total 5,227 events were recorded across different categories urban arterials. The results showed facilities provided greater bicycles vehicles. Passing maneuvers less than...

This paper makes use of a probabilistic model that predicts the likelihood crashes (crash potential) on freeways basis traffic flow conditions, in real-time crash prevention. The was developed using incident logs and loop detector data collected over 13-month period Gardiner Expressway Toronto. Previous work suggested an increase levels turbulence generally yields high potential. Traffic defined terms series precursors represent conditions were present prior to occurrence. To apply...

Travel time is viewed by travelers and road managers as one of the key indicators quality service. Bluetooth detectors have recently emerged a viable technology for acquisition vehicle travel times. Several studies described application to freeways compared measured times with obtained through other technologies. This paper examines arterial The environment substantially more challenging than freeway because frequent interruptions in traffic flow caused signals. magnitude errors detection...

The conditional generative adversarial network (CGAN) is used in this paper for empirical Bayes (EB) analysis of road crash hotspots. EB a well-known method estimating the expected frequency sites (e.g. segments, intersections) and then prioritising these to identify subset high priority hotspots) additional safety audits/improvements. In contrast conventional approach, which employs statistical model such as negative binomial (NB-EB) data, recently developed CGAN-EB approach uses network,...

Transportation modeling frameworks assume that travelers are economically rational; is, they choose the lowest-cost alternative to complete a desired trip. The reliability of travel time is critical importance travelers. ability quantify allows planners estimate more accurately how system performance influences local behavior and evaluate appropriately potential investments in transportation infrastructure. This paper presents methodology makes use automatic vehicle location data from...