Roundabouts increase time

Roundabouts would improve intersections along U.S. 41, but would actually slightly increase travel time from the barrier islands. Those were the findings of a connectivity study presented to city commissioners June 16.

The connectivity plan would create five roundabouts on U.S. 41, slow the speed limit from 45 mph to 35 mph and install wider, landscaped medians.

The city’s connectivity consultant, Trans Associates, created an animated simulation that showed cars moving through five proposed roundabouts along the bayfront.

The computer-generated simulation demonstrated how vehicles would flow smoothly through the roundabouts, instead of stacking up at traffic lights.

Trans Associates also conducted a time trial from U.S. 41 and Osprey Avenue to Longboat Key Town Hall and back. The results showed roundabouts would make the trip to Longboat Key about 10 seconds longer and the trip back to Osprey Avenue about one minute longer.

Jason Collins, Trans Associates senior manager, said the time difference is the result of a lower speed limit on U.S. 41.

City planner Steve Stancel presented an implementation schedule in two phases. Phase A would take up to three years and would consist mainly of design work. Phase B would take up to 20 years to complete and includes most of the construction work.

Phase A’s estimated cost is $2.2 million. Phase B is expected to cost $35.6 million.
Commissioner Kelly Kirschner suggested instead of spending three years just designing several connectivity features, it might be better to use that time to create one roundabout at U.S. 41 and 10th Street and see how drivers like it.

The commission will have the chance to discuss changes to the proposal when they hold a connectivity public hearing within the next couple of months.