Connected Vehicle Data-Based Tools for Work Zone Active Traffic Management

Work zones present challenges to safety and mobility that require agencies to balance limited resources with vital traffic management activities. It is important to obtain operational feedback for successful active traffic management in work zones. Extensive literature exists regarding the impact of congestion and recommendations for work zone design to provide safe and efficient traffic operations. However, it is often infeasible or unsafe to inspect every work zone within an agency’s jurisdiction. This dissertation outlines the use of connected vehicle data, crash data, and geometric data from mobile light detection and ranging (LiDAR) technology for active traffic management in work zones. Back-of-queue crashes on high-speed roads are often severe and present an early opportunity for leveraging connected vehicle data to mitigate queueing. The connected vehicle data presented in this dissertation provides compelling evidence that there are significant opportunities to reduce back-of-queue crashes by warning drivers of unexpected congestion ahead. In 2014 and 2015, approximately 1% of the total mile-hours of Indiana interstates were operating below 45 MPH and were considered congested. Congested conditions were observable in the connected vehicle data prior to 18.5% of all interstate crashes. The congested crash rate was found to be 20.6-24.0 times greater than the uncongested crash rate. A real-time queue alert system was developed to detect queues and notify INDOT personnel via email. When average speeds drop below 45 MPH, queue monitoring algorithms are triggered, and an alert is sent to selected individuals. Still camera images, work schedules, and crash reports were used to ground-truth the alert system. The notification model could be easily extended to in-car notification. A weekly work zone report was developed for use by the Indiana Department of Transportation (INDOT) for the purpose of assessing and improving both mobility and safety in work zones. The report includes a number of graphs, figures, and statistics to present a comprehensive picture of performance. This weekly report provided a mechanism for INDOT staff to maintain situational awareness of which work zones were most challenging for queues and during what periods those were likely to occur. These weekly reports provided the foundation for objective dialog with contractors and project managers to identify mechanisms to minimize queueing and allocate public safety resources. Lastly, this dissertation discusses the integration of LiDAR-generated geometric data with connected vehicle speed data to evaluate the impact of work zone geometry on traffic operations. A LiDAR-mounted vehicle was deployed to a variety of work zones where recurring bottlenecks were identified to collect geometric data. The advantages and disadvantages of the technology are discussed. A number of case studies demonstrate versatility of the technology in transportation applications

Characterizing Interstate Crash Rates Based on Traffic Congestion Using Probe Vehicle Data

Crash reduction factors are widely used by engineers for prioritizing safety investments. Work zones are routinely analyzed by the length and duration of queues. Queue detection warning technology has been growing in availability and reliability in recent years. However, there is sparse literature on the impact of freeway queueing on crash rates. This paper analyzes three years of crash data and crowdsourced probe vehicle data to classify crashes as being associated with queueing conditions or free flow conditions. In 2014, only 1.2% of the distanced-weighted hours of operation of Indiana interstates operated at or under 45 MPH. A three-year study on Indiana interstates indicates that commercial vehicles were involved in over 87% of back-of-queue fatal crashes compared to 39% of all fatal crashes during free flow conditions. A new measure of crash rate was developed to account for the presence and duration of queues: crashes per mile-hour of congestion. The congested crash rate on all Indiana interstates in 2014 was found to be 24 times greater than the uncongested crash rate. These data were also separated into both rural and urban categories. In rural areas, the congested crash rate is 23 times the uncongested crash rate. In urban areas, the congested crash rate is 21 times the uncongested crash rate. Queues are found to be present for five minutes or longer prior to approximately 90% of congestion crashes in 2014. Longer term, this information shows the importance in the development of technology that can warn motorists of traffic queues

Leveraging Commercial Cloud Navigation and Maps for Special Event Route Management

Universities and sports venues routinely host large events that often attract over 100,000 attendants. These special events create and encounter unique challenges, such as motorists unfamiliar with the area, streets that must be closed for security and crowd management, non-traditional parking, and strong demand immediately after the event. Traditionally, special parking and routing plans have been communicated by static maps and, more recently, static maps posted on web sites. This presentation discusses the implementation of cloud-based maps (maps.google.com) that provide recommended turn by turn directions to and from 26 parking lots associated with the Purdue Football home game activities. These maps were developed in close coordination with public safety and athletics staff. The resultant maps were communicated to season pass holders and other visitors using QR codes printed on parking passes as well as a variety of electronic media. In addition to covering the map generation process, this presentation will share some of the lessons learned and ongoing activities related to special event management

Characterizing Interstate Crash Rates Based on Traffic Congestion Using Probe Vehicle Data

Crash reduction factors are widely used by engineers for prioritizing safety investments. Work zones are routinely analyzed by the length and duration of queues. Queue detection warning technology has been growing in availability and reliability in recent years. However, there is sparse literature on the impact of freeway queueing on crash rates. This paper analyzes three years of crash data and crowd-sourced probe vehicle data to classify crashes as being associated with queueing conditions or free flow conditions. In 2014, only 1.2% of the distanced-weighted hours of operation of Indiana interstates operated at or under 45 MPH. A three-year study on Indiana interstates indicates that commercial vehicles were involved in over 87% of back-of-queue fatal crashes compared to 39% of all fatal crashes during free flow conditions. A new measure of crash rate was developed to account for the presence and duration of queues: crashes per mile-hour of congestion. The congested crash rate on all Indiana interstates in 2014 was found to be 24 times greater than the uncongested crash rate. These data were also separated into both rural and urban categories. In rural areas, the congested crash rate is 23 times the uncongested crash rate. In urban areas, the congested crash rate is 21 times the uncongested crash rate. Queues are found to be present for five minutes or longer prior to approximately 90% of congestion crashes in 2014. Longer term, this information shows the importance in the development of technology that can warn motorists of traffic queues

Variable Speed Limit Study Upstream of an Indiana Work Zone with Vehicle-Matching

Managing traffic in workzones presents significant mobility and safety challenges for agencies. The goals of a workzone traffic management plan are to safely slow vehicles ahead of the workzone, maintain speeds that provide for the safety of motorists and construction workers, and manage the growth of queues. Variable speed limits have historically been presented as a technology that can dynamically regulate speed in response to prevailing traffic conditions. However, techniques used to evaluate the impact of variable speed limits typically use aggregated statistics such as mean and standard deviation to determine the “typical” speed reduction. This paper presents a new methodology to evaluate the impact of variable speed limit signage based on individual vehicle-matching. The speeds and speed changes of these matched vehicles were used to analyze individual driver response to the variable speed limits. This allows agencies to understand the impact variable speed limit signage has on the distribution of vehicle speeds. It was concluded that vehicles need to observe multiple signs prior to any tangible reduction in speed limit. Placing signs on both shoulders and in multiple longitudinal locations have a greater impact on speeds than a single sign

Performance Ranking of Arterial Corridors Using Travel Time and Travel Time Reliability Metrics

Performance measures are important for managing transportation systems and demonstrating accountability. This session presents a scalable methodology for analyzing arterial travel times, taking into account both the central tendency of the travel time and its reliability. Findings will be presented from a pilot analysis that was carried out for 28 arterials including a total of 341 signalized intersections from across the state of Indiana

Evaluation of Mobile Advanced Road Weather Information Sensor (MARWIS) by Lufft for Indiana Winter Road Operations

The students of the Field Infrastructure Assessment course evaluated the Mobile Advanced Road Weather Information Sensor by Lufft on behalf of the Indiana Department of Transportation. The device is mounted on a vehicle, takes roadway condition measurements 100 times per second, and aggregates the measurements into one-second intervals. The data is transmitted real-time to the cloud. The class specifically evaluated the following measurements: road condition, surface temperature, and friction. It was found that the MARWIS temperature reading was systematically 4˚F lower than the probe readings. Skid test empirical results were consistent with the MARWIS friction readings. It was also found, using two devices on the back of the test vehicle, that the friction in the wheel track was greater than the friction in the center of the lane, as expected. Lastly, the “chemically wet” road condition was not consistently observed by MARWIS where expected

2013–2014 Indiana Mobility Report: Summary Version

The 2013–2014 Indiana Mobility Report: Summary Version examines the mobility performance of Indiana’s state highway system. Minute-by-minute crowdsourced probe vehicle speed data and vehicle volume data were used to develop performance measures that identify, quantify, and visualize the location and duration of congestion on Indiana Interstates. The summary report presents overall system performance, including a monthly overview covering January 2011 through June 2014 as well as selected highlights of significant projects. In addition to the Interstate system, the report characterizes selected high-priority arterial corridors to rank their mobility performance in terms of travel time and travel time reliability