Kentucky Transportation Cabinet
Bowling Green, KY
Western Kentucky University students, faculty and area residents have a smoother commute with the addition of a modern roundabout near the southern campus gateway.
An existing four-way signalized intersection located at U.S. 31W (Nashville Road) and U.S. 231X (University Boulevard) was causing significant traffic congestion and safety concerns. Between 2001 and 2011 there were over 500 accidents at this busy intersection. Burgess & Niple (B&N) designed a new two-lane roundabout to replace the signalized intersection that has improved traffic flow, safety and mobility for area motorists, bicyclists and pedestrians.
Improved Traffic Flow and Safety
The continuous movement of traffic through the modern roundabout at this intersection helps reduce congestion and delays. The new roundabout improved safety by reducing the number of potential conflict points. Typically, modern roundabouts reduce vehicular conflict points from 32 at a standard intersection to eight. Roundabouts reduce pedestrian conflict points from 24 at a standard intersection to eight. In addition, roundabout geometrics encourage speed reduction, which in turn reduces crash severity.
Just north of the intersection, left-turning movements onto Chestnut Street, and other side streets, significantly contributed to the back-ups and delays. To address this, a raised median, north of the roundabout, was extended to eliminate left-hand turns onto Chestnut from US 31W. All left-turn traffic from Chestnut is now directed through the roundabout. These changes also have improved safety and overall traffic movement.
Reduced Construction Costs
To help reduce construction costs, the existing U.S. 31W two-lane road with a center turn lane was restriped to become two southbound lanes and one northbound lane south of Oaklawn Way. Using the center turn lane as an additional lane eliminated the need to widen the existing road. In addition to costing more to construct, widening the road would have required the purchase of additional right of way and the relocation of existing utilities. This roundabout also costs less to operate than the original signalized intersection because it does not require electricity.
Minimal Impact on Local Traffic
The project schedule was expedited so that construction could take place over Western Kentucky University’s summer break to reduce the impact on local traffic. In addition, a phased construction approach allowed traffic to keep moving through the intersection. First, motorists used the existing road while the majority of the roundabout was built next to it. Then traffic was shifted to the newly constructed pavement while the remaining portion was built. This approach allowed the intersection to remain open for all but eight days during construction.
Honors and Awards
The Bowling Green Roundabout project received a 2015 Transportation Improvement Award from the American Society of Highway Engineers (ASHE) Derby City Section in the “$5 Million and Under” category.