Speed Enforcement in Work Zones and Synthesis on Cost-Benefit Assessment of Installing Speed Enforcement Cameras on INDOT Road Network

Work zone safety is a high priority for transportation agencies across the United States. High speeds in construction zones are a well-documented risk factor that increases the frequency and severity of crashes. It is therefore important to understand the extent and severity of high-speed vehicles in and around construction work zones. This study uses CV trajectory data to evaluate the impact of several work zone speed compliance measures, such as posted speed limit signs, radar-based speed feedback displays, and automated speed enforcement on controlling speeds inside the work zone. This study also presents several methodologies to characterize both the spatial and temporal effects of these control measures on driver behavior and vehicle speeds across the work zones

Indiana Interstate Speed Profiles 2018–2022

Systemwide interstate performance measures that detail hours and location of congestion on an interstate provide important information for decision makers to plan capital projects and assess operations. This report presents summary of mile-hours of congestion across 8 Indiana interstates and the Indiana toll road. Hours of operation by speed bins (0 to 14 mph, 15 mph to 24 mph, 25 mph to 34 mph, 35 mph to 44 mph, 45 mph to 54 mph, 55 mph to 64 mph, more than 65 mph) for every 0.1 mile of the interstates across a month were tabulated for every hour of every day during the month. The quantities of those six different speed bins are plotted as a stacked bar plot from lower to higher speeds by mile marker for each month. The vertical axis shows the mile marker of the interstate. Horizontally, these stacked bars are cropped at maximum of 250 hours (a little more than 10 days) per month to focus on the lower speeds. To produce these plots, approximately 60 billion records from INRIX across 5 years were analyzed. These speed profiles help identify areas with congestion at system level as well as regions impacted by severe winter storms and construction projects

Implementation of Enhanced Probe Data (CANBUS) for Tactical Workzone and Winter Operations Management

For over a decade, segment-based probe data has been extensively used by transportation stakeholders for monitoring mobility on Indiana roadways. However, enhanced probe data from connected vehicles includes a richer dataset that can provide more detailed real-time and after-action reviews. This enhanced data includes detailed vehicle trajectories, at 3s resolution, and “event data.” This event data is near real-time and includes hard-braking events, hard-acceleration events, weather-related data, including wiper activations and some seat belt usage data. This project developed a set of methodologies and resulting visualizations that enables the use of emerging connected vehicle data in operational decision-making on work zone management and winter operations activities. Each month approximately 13 billion connected vehicle records are ingested for Indiana. During peak periods, approximately 625,000 records per minute are ingested. Without substantial processing, this large data set is “data-rich, information-poor.” This study developed techniques to rapidly assign relevant data to interstate segments so that visual graphics could be efficiently generated. This provided the ability for both real-time monitoring as well as after action assessment to identify opportunities to improve both work zone operations and winter operation activities. The summaries derived from these datasets have helped promote effective actionable dialog among agencies, contractors, and public safety colleagues towards the overarching goal of improving interstate safety and mobility

Impacts to Traffic Behavior from Queue Warning Truck: Current Pilot Project

The Indiana Department of Transportation (INDOT) started deploying queue warning trucks ahead of interstate work zones to alert motorists of queued traffic. Along with visually alerting the motorists, digital alerts were integrated with navigational applications such as Apple Maps, Waze, and the in-vehicle infotainment system of Stellantis vehicles. More than 45,000 hours of alerting was provided to motorists across various interstates in Indiana over a 26-month period. This report evaluated the impact of queue warning trucks on traffic using hard braking events and traffic speeds provided by granular connected trajectory vehicle data. Evaluation of over 370 hours of queuing with the presence of queue trucks and 52 hours of queuing without the queue trucks indicated a decrease in hard braking events by 80% when trucks were present with digital alerts. It was also observed that traffic speeds started to reduce approximately 1,500 to 2,000 ft in advance of deployed queue trucks

Extraction of Vehicle CAN Bus Data for Roadway Condition Monitoring

Obtaining timely information across the state roadway network is important for monitoring the condition of the roads and operating characteristics of traffic. One of the most significant challenges in winter roadway maintenance is identifying emerging or deteriorating conditions before significant crashes occur. For instance, almost all modern vehicles have accelerometers, anti-lock brake (ABS) and traction control systems. This data can be read from the Controller Area Network (CAN) of the vehicle, and combined with GPS coordinates and cellular connectivity, can provide valuable on-the-ground sampling of vehicle dynamics at the onset of a storm. We are rapidly entering an era where this vehicle data can provide an agency with opportunities to more effectively manage their systems than traditional procedures that rely on fixed infrastructure sensors and telephone reports. This data could also reduce the density of roadway weather information systems (RWIS), similar to how probe vehicle data has reduced the need for micro loop or side fire sensors for collecting traffic speeds

Dashboards for Real-time Monitoring of Winter Operations Activities and After-action Assessment

The Indiana Department of Transportation (INDOT) operates a fleet of nearly 1100 snowplows and spends up to $60M annually on snow removal and de-icing as part of their winter operation maintenance activities. Systematically allocating resources and optimizing material application rates can potentially save revenue that can be reallocated for other roadway maintenance operations. Modern snowplows are beginning to be equipped with a variety of Mobile Road Weather Information Sensors (MARWIS) which can provide a host of analytical data characterizing on-the-ground conditions during periods of wintry precipitation. Traffic speeds fused with road conditions and precipitation data from weather stations provide a uniquely detailed look at the progression of a winter event and the performance of the fleet. This research uses a combination of traffic speeds, MARWIS and North American Land Data Assimilation System (NLDAS) data to develop real-time dashboards characterizing the impact of precipitation and pavement surface temperature on mobility. Twenty heavy snow events were identified for the state of Indiana from November 2018 through April 2019. Two particular instances, that impacted 182 miles and 231 miles of interstate at their peaks occurred in January and March, respectively, and were used as a case study for this paper. The dashboards proposed in this paper may prove to be particularly useful for agencies in tracking fleet activity through a winter storm, helping in resource allocation and scheduling and forecasting resource needs

Integration of Probe Data Tools into TMC Operations

With the advent of probe data, there is a need to virtualize many of the Traffic Management Center (TMC) tools used for analyzing work zones, severe crashes, winter operations, moving maintenance operations, and providing dashboards characterizing overall system mobility. Traditional tools have evolved over the past several years and it is important to develop training materials and make them more accessible to a broad range of Indiana Department of Transportation (INDOT) users and other stakeholder. Over the past several years, agencies have used probe data, mainly 1-minute aggregated segment-based probe data to assess and manage roadways. This study extended traditional segment-based probe data concepts to include enhanced trajectory-based connected vehicle (CV) data, which provides anonymous individual vehicle waypoints at a reporting interval of 3 seconds within a 1.5-meter fidelity radius. The study discusses some of the near-term opportunities, nationwide scalability, and some of the limitations of trajectory data for managing roadways and infrastructure assessment. The tools developed in this study will assist INDOT and other stakeholders in visualizing interstate queues, identifying back-of-queue hard braking events and crashes, identifying alternate diversions during incidents and road closures, enhancing agile management of work zones, estimating traffic signal performance measures without infrastructure investment, and understanding the impact of construction diversions on traffic signals performance

Crowdsourcing/Winter Operations Dashboard Upgrade

INDOT has recently completed the deployment of Parsons telematics-based dash-cameras, automatic vehicle locator (AVL) positions, and spreader rate monitoring across their winter operations fleet. The motivation of this study was to develop dashboards that integrate connected vehicle data into the real-time monitoring and after-action review of winter storms. Each month approximately 13 billion connected vehicle records are ingested for the state of Indiana and almost 99 billion weather data records are ingested nationwide in 15-minute intervals. This study developed techniques to utilize this connected vehicle data and weather data to monitor real-time mobility of interstates and post storm after-action assessments to identify improvement opportunities of winter operations activities. In multiple instances, these agile reviews have influenced operational changes in snow removal and maintenance around the state, leading to a marked improvement in observed mobility and safety