Areas of construction on the roads, and the work zones that get set up around them, can cause headaches when it comes to traffic. But traffic is not the only issue Departments of Transportation (DOTs) are focused on solving when it comes to work zones. Most work zones require a detour, lane closure, or decreased speed limit, and it’s any one of these changes to the normal flow of traffic that can actually increase the risk of incidents. In 2019, there were 115,000 crashes in work zones and of that number, 27,000 resulted in injury and 762 in fatalities.
We talked with Purdue University about their partnership with Indiana DOT to understand what they are doing to improve safety around work zones and how connected vehicle data (CVD) is helping to mitigate accidents, and ultimately keep drivers and workers safe.
The Problem: Understanding why accidents happen near work zones
The first priority for Purdue and Indiana DOT in improving work zone safety was to better understand why and how accidents were occurring near work zones. They did this by analyzing accident reports and using vehicle movement insights to understand when hard braking events were happening. Hard braking events are situations in which a driver, or multiple drivers, had to slam their brakes to come to an abrupt stop. Through data analysis, the team quickly uncovered a strong correlation between accidents and hard braking events.
The Solution: Using CVD to mitigate hard braking events
Once Purdue and Indiana DOT came to understand that hard braking could be used as a surrogate measure of safety near a work zone, it was time to start monitoring where hard braking events were happening. CVD enabled Indiana DOT to look at hard braking events in near real time – seeing trends in hours or days, instead of the weeks or months that it used to take to understand traffic patterns using roadside cameras.
Wejo’s connected car data showed where hard braking events were happening, at which mile marker, at which times of day and proximity to the work zone itself. The team identified that the hard braking events were happening because of the “queue”, the line of vehicles slowed or stopped due to a construction zone. These lines in many cases were backing up far from where the actual work zone and cautionary signage was located, meaning drivers were not expecting a slowdown when they hit the queue. The team then concluded that hard braking events could potentially be avoided by implementing advanced warning vehicles upstream from the queue. Purdue and Indiana DOT used CVD to triage where the most important locations across the state were for new queue trucks and to determine the proximity to the back of the queue they should be deployed.
The Results: Measuring impact of mitigation efforts with CVD
After initial deployment, it was critical for Purdue and Indiana DOT to measure if the mitigation efforts were successful in decreasing hard braking events. To do that, they analyzed activity in two separate work zones – one with a queue truck tactfully positioned using CVD and one without. The number of hard breaking events in the work zone with the queue truck was significantly less than the area without it. Using CVD reduced the number of hard braking events by more than half.
Data for good
This use case underscores the value CVD has not only in helping reduce traffic congestion, but also in reducing hard braking events and ultimately the crashes they cause. The analysis from Purdue and Indiana DOT suggests that cutting hard braking events in half could reduce crashes by 50 percent, meaning a dramatic decrease in injury and fatalities near work zones. At Wejo, we are dedicated to using data for good and we are proud our CVD has been fundamental in projects, including with the team at Purdue and Indiana DOT, that are making the world a safer, better place to live. If you want to hear more about how CVD is helping improve work zone safety. Check out the full webinar with Purdue University, Indiana DOT and Google, "Connecting the DOTs: How Connected Vehicle Data Improves Safety”