Planners in Louisiana found that only 3.8% of roadspace accounted for most congestion — allowing them to mitigate in key trouble spots.
The Shreveport, Louisiana metro in the state’s northwest corner embodies the complexity of many regional hubs. Near the Texas and Arkansas borders, it also encompasses three interstates, four parishes, as well as a major military site, Barksdale Airforce Base. Roadways must bridge two significant waterways, Cross Lake and Red River.
To plan transportation, the region relies on the NLCOG (Northwest Louisiana Council of Governments), a Metropolitan Planning Organization or MPO.
Like planning bodies everywhere, NLCOG must battle traffic congestion. It’s not just a matter of responding to citizens’ frustrations. Traffic issues cause real economic damage through unproductive time, increased fuel spending, environmental impacts, and road-safety issues.
But when planners at NLCOG set out to draw up their 2021 Congestion Management Process study or CMP, which is federally mandated, they faced a real obstacle.
To pinpoint the exact traffic management trouble spots and causes of congestion, they needed robust and comprehensive data and reliable insights across their study area.
The planners used StreetLight to access in-depth data insights across all the study area’s roadways. NLCOG utilized the StreetLight InSight® platform for traffic flow data, including traffic volume, speed, travel time and other metrics as well.
More granularity and refreshable insights
Specifically, StreetLight’s traffic Metrics helped the planners calculate a key metric: Speed Reduction Factor or SRF, which is a standard ratio for measuring congestion.
SRF numbers quickly pinpointed the specific trouble spots responsible for most traffic congestion.
‘Without StreetLight Data, calculating the Speed Reduction Factor would have been monumental … in terms of staff time and resources,” says Chris Petro, deputy director and transportation manager at NLCOG.
What did planners find?
Using SRF results, the planners discovered that 96% of the mileage in the 13 study corridors showed no congestion or only “Moderate” congestion levels. Only six out of the 158 miles examined were found to be “Severely Congested.”
The results also pinpointed that three corridors out of the 13 had over a mile of severely congested traffic, and showed the exact location of these priority segments.
For example, the Airline Dr. corridor was found to contain 1.55 miles of “Severely Congested” segments during peak-PM. Airline Dr., east of Red River in Bossier City, runs under both interstates 20 and 220 and stretches south into the neighborhood of the Airforce base.
Further analysis revealed the worst delays were not occurring on freeways or interstates, but instead at intersections and on road sections with inadequately spaced signals near interstate on-ramps.
The CMP study, adopted by NLCOG earlier this year, made new recommendations and endorsed various in-flight plans and projects. These included investments in new highway on-ramp signaling, intersection signage, and improved capacity in certain corridors.
A closer look at how other regions can generate traffic insights with StreetLight’s platform
To calculate and visualize travel speeds in the 13 study corridors, NLCOG planners relied heavily on StreetLight InSight®.
Planners and agencies all over North America are utilizing StreetLight’s Metrics to perform Corridor Studies, and more. The platform allows for analyses of specific segments through a user-friendly graphical interface and intuitive visualizations, as well as downloadable CSV files. With a few clicks, planners can zero in on one road segment and quickly visualize changes in travel speed and volume over time, and also understand how traffic moves through a larger road system.
- The platform’s Segment Analysis tool examines key traffic metrics on a selected roadway. The features include a distribution chart that reveals when travel peaks within corridors, as well as a speed distribution chart that measures how traffic speeds fluctuate throughout the day.
- Other tools include Origin-Destination Analysis, which examines how vehicle and bicycle travelers disperse within the road system. Manual replication of the analysis in this demonstration video would have required 90-day monitoring of multiple transportation modes at 36 locations with traditional methods.
- Finally, the Top Routes Analysis examines the origin of traffic flow entering a corridor and where it disperses once passing through a corridor.
A video demonstration focused on a portion of Portland Street in Halifax, Nova Scotia shows how planners can utilize three of the platform’s analytical tools for their own needs: the Origin-Destination Analysis, the Segment Analysis, and the Top Routes Analysis.
The platform allows planners access to historical and updated Metrics across multiple transportation modes for nearly every roadway in North America in a few clicks.