NDOT devices capture near-crash traffic data in Nashville, Tennessee

NASHVILLE, Tenn. (WKRN) — The Nashville Department of Transportation has installed the first in a series of LiDAR devices in North Nashville with the goal of collecting data that can be turned into driver and pedestrian safety improvements.

LiDAR (Light Detection and Ranging) devices emit lasers that map objects in three dimensions. They differ from cameras in that they do not capture images of individuals or their faces.

“I think the key point we're trying to make to the community is that this is not surveillance technology,” said Derek Hagerty, NDOT's chief traffic engineer. “Cameras certainly have their place in security. But these LiDAR devices give us the ability to capture much of the same information through an anonymous system.

NDOT just installed the first of seven devices at the intersection of Clarksville Pike and 26th Avenue in North Nashville. The facility will continue on Clarksville Pike to Buchanan, then through Buchanan, to Hwy. So in total, they're looking at a two-plus mile stretch that will have seven facilities.

“About half of them will be at signalized intersections, the other half will be in the middle of a crossing,” Hagerty said. “This is extremely important because we know that the majority of our pedestrian deaths do not occur at crosswalks. This happens when pedestrians cross at other locations. We want to make sure that no matter where pedestrians cross, they can do so safely.

The first phase of the project is funded by a $2 million SMART grant from the U.S. Department of Transportation. NDOT will apply for a $20 million grant for expansion in Nashville.

The goal is to capture near-miss traffic data, because researchers usually get their traffic information from an accident, but if there isn't one, they still want to know what happened. has passed and what changes can be made to make streets safer for drivers and pedestrians.

“The areas where we're testing this program have bus stops, a brand new transit center, and then police stations, bike lanes and sidewalks,” he said. “It gives us a really good overview of all the different types of interaction.” So we understand how all of this happens, how all of these different modes interact with each other.

This is part of Metro's Vision Zero action plan to reduce traffic deaths and injuries in Nashville. NDOT is partnering with Tennessee State University, Vanderbilt University and UT Chattanooga to roll out the project.

“An average intersection can accommodate between 20,000 and 30,000 vehicles, pedestrians, cyclists and public transport users each day. If we only see a few accidents a year, we only collect a very small amount of that data,” Hagerty said. “These LiDAR devices allow us to capture data on every motion interaction that occurs there. And because LIDAR works in a three-dimensional field, we're able to see how far away they're happening and, essentially, identify near misses.

Hagerty said they will use the data to install security countermeasures in real time. People will see things like signal timing updates, signage directly tied to signals that will flash when pedestrians cross the street to alert drivers, and you'll likely see new mid-block crossings added over the next two months.

“This project allows us to anticipate the data a little bit instead of waiting for these crashes to happen,” Hagerty said. “We can identify areas with data where we know accidents are possible because of the number of near misses. This allows us to resolve these issues before someone is injured or, worse yet, killed. »