The Choice Is Clear

We strongly support the single-lane roundabout design for the Shelburne St. intersection because it is safer, cheaper, and less intrusive than other alternatives. We urge that the Burlington City Council accept the recommendations of traffic planning studies, the Burlington DPW, and VTrans so that this important project can move forward. Here are our reasons:

A single-lane design provides safety and traffic flow at lowest cost
Estimated Construction Cost: $895,000
Benefit/Cost ratio = 1.37

PROS:
• Safer for cars than 2 lane alternatives (72% crash reduction)
• Safer for bicycles (slower traffic)
• Safer for pedestrians (narrower pedestrian crossing is safer and quicker)
• Better vehicle speed control with single lane entry
• Better queuing performance for worst movement (southbound on St. Paul St.)
• Costs less: less pavement, smaller intersection, less maintenance, no additional right-of-way needed

CONS:
• Northbound lanes must merge before entering causing longer moving queues during peak times

A 2-lane roundabout is more expensive and less safe
Estimated Construction Cost $1,034,000
Benefit/Cost ratio = 0.91

PROS:
• Less delay and shorter queues for northbound approach at peak traffic, 2019

CONS:
• Likely to be more accidents (sideswipes occur where 2 lanes)
• More dangerous for bicycles (less speed and lane control)
• More dangerous for pedestrians (longer crossing distances, faster traffic)
• More delays and longer queues for St. Paul approach
• Costs more: more pavement, more maintenance, and more right of way intrusion onto neighbors

Traffic studies show that even at peak traffic in 2019, the 2 lane design will result in only marginal reductions in average traffic delays on Shelburne St. (3.8 vs. 4.7 seconds) and will actually increase overall delays when all approach directions are considered.

Safe and efficient movement of trucks and other large vehicles and emergency vehicles has been addressed in single-lane design.

Vermont Highway Safety Program will pay 100% of the cost of single-lane roundabout, but not for the 2 lane design.