Maintaining traffic flow as they reduce speeds and conflict points, roundabouts are increasingly becoming the smart intersection solution.
Roundabouts Boost Safety in Pennsylvania and Beyond
Recent data published by the Pennsylvania Department of Transportation (PennDOT) shows a significant decrease in crashes, injuries, and fatalities at intersections in the state where roundabouts have been installed. PennDOT has begun requiring that roundabout alternatives be included in every intersection study performed for the agency for which roundabouts are feasible, a move the promises to have a growing positive effect on driver and pedestrian safety throughout the state.
NEWSCAST VIDEO
A WPMT Fox 43 report on the roundabout study includes comments from PennDOT Safety Press Officer Fritzi Schreffler.
Compelling Data Supports Benefits
Data collected from 11 intersections included in the PennDOT study reveal a 47-percent reduction in the total number of vehicle collisions and a 100-percent decrease in fatalities and serious injuries. Safety benefits like these are also reflected in data on roundabouts from sites nationwide compiled by the Insurance Institute for Highway Safety/Highway Loss Data Institute.
Increased Safety for Drivers and Pedestrians
Speed reduction is a key safety feature of roundabouts. As drivers need to slow when entering the roundabout, they have more time to make decisions and that speed reduction also helps lessen the severity of an accident should one occur—a significant contributing factor to the reduction in serious injuries and fatalities.
Roundabouts also simplify the driver’s decision-making process. In traditional intersections, drivers may have to judge traffic coming from many directions. In a roundabout, the driver only has to look in one direction—to the left in the U.S.—in order to determine if they can proceed.
Roundabouts boost safety for pedestrians as well as motorists. To help simplify the drivers’ decision-making process, pedestrian crosswalks can be located a few car lengths before the roundabout entry point. This makes pedestrians become the sole priority at the crosswalk location and drivers can concentrate strictly on other vehicles as they enter traffic.
Simplified Maintenance
While safety is the number one concern, roundabouts have the additional benefit of being relatively low maintenance. Roundabouts are non-signalized by and large, which reduces the need to allocate funds and personnel for signal upkeep. Once they are installed, the only maintenance most roundabouts require is occasional landscaping.
Flexibility Tailored to Traffic Flow
While roundabouts are generally held to best accommodate traffic flow up to 20,000 vehicles per day, their capacity can be increased with some simple modification. For instance, traffic flow that is heavy or dominant from one direction may cause delays at a given roundabout entrance point as drivers will not be able to join the flow of traffic—and as roundabouts are traditionally non-signalized, there is no way to create traffic gaps. This type of situation can be addressed by adding a ‘metering signal’ featuring automated traffic detection that can regulate heavy or dominant traffic and give all drivers the chance to enter the roundabout. This solution allows the roundabout to compensate for intermittent traffic increases and retain its ‘free-flowing’ attributes during less heavily traveled hours.
The use of roundabouts has increased exponentially—as the data shows, the trend is going a long way toward improving safety.
Smart Solutions, Safer Intersections
As in any intersection situation, there may be multiple solutions—and GAI transportation engineers evaluate the positives and negatives of each strategy to come up with the option that will best serve the desired outcomes. Review of trends over the last 20 years show that the use of roundabouts has increased exponentially over that time—and as the data shows, the trend is going a long way toward improving safety.
