A tanker truck overturned in the roundabout on Hwy. 171, adjacent to the Market Basket Grocery store, around 7:15 p.m. on Thursday.

A tanker truck overturned in the roundabout on Hwy. 171, adjacent to the Market Basket Grocery store, around 7:15 p.m. on Thursday.

Leesville Mayor, Rick Allen, said, "The GPS equipment on the truck that overturned in the traffic circle, says the truck was traveling at 18 MPH at the time it turned over." This is too fast, he said.

The truck was carrying 6,000 pounds of caustic soda, said Allen. "It had to be pumped out so there was no chance of a spill when turning the truck and trailer upright."

A hazmat crew and the Louisiana Department of Environment Equality (DEQ) were on scene, along with the Leesville Fire and Police Departments. By 5 a.m. Friday morning, they had Hwy. 171 northbound open but southbound remained closed until around 2 p.m., said Allen. 

Several readers posted to Facebook, in response to this accident, that the very nature of the traffic circle is to blame for this sort of accident. Others posited that the issue was not the structure of the road at fault, but the method of the driver.

The Federal Highway Administration Office of Safety (FHAOS) identified roundabouts as a proven safety countermeasure because of their ability to substantially reduce the types of crashes that result in injury or loss of life. Roundabouts are designed to improve safety for all users, including pedestrians and bicycles.

They are often safer, more efficient, less costly and more aesthetically appealing than conventional intersection designs, per FHAOS research.

The American Association of State Highway and Transportation Officials Highway Safety Manual states that "roundabouts reduce the types of crashes where people are seriously hurt or killed by 78-82% when compared to conventional stop-controlled and signalized intersections."

According to guidelines put forth by the National Cooperative Highway Research Program, drivers approaching a roundabout have two basic decisions to make upon navigating a roundabout. They must select the appropriate lane for their intended destination, and yield to those who have the right-of-way.

 Making navigating decisions in roundabouts is generally more complex than for other intersection types, mainly because the driver cannot always see the exit or destination and the fact that the intersection is curved requiring drivers to gradually change direction, potentially disorienting a driver.

The safety performance of a roundabout is a product of its design. At roundabouts, vehicles travel in the same direction, eliminating the right-angle and left- turn conflicts associated with traditional intersections. In addition, a good roundabout design places a high priority on speed control. Lower vehicle speeds are intended to provide the following safety benefits--

Provide more time for entering drivers to judge, adjust speed for, and enter a gap in circulating traffic, allowing for safer merges;

Reduce the size of sight triangles needed for users to see one another;

Increase the likelihood of drivers yielding to pedestrians (compared to an

uncontrolled crossing);

Provide more time for all users to detect and correct for their mistakes or mistakes of others;

Make crashes less frequent and less severe, including crashes involving pedestrians and bicyclists; and

Make the intersection safer for novice users.

This particular roundabout on Hwy. 171 "was designed and installed by DOTD engineers with the understanding of high volume commercial traffic," said Allen. 

Roundabouts are designed to accommodate vehicles of all sizes, including emergency vehicles, buses, farm equipment and semi-trucks with trailers. Oversize vehicles and those with trailers may straddle both lanes while driving through a roundabout.

Many roundabouts are designed with a truck apron, a raised section of pavement around the central island that acts as an extra lane for large vehicles. The back wheels of the oversize vehicle can ride up on the truck apron so the truck can easily complete the turn, while the raised portion of concrete discourages use by smaller vehicles.

Because large vehicles may need extra room to complete their turn in a roundabout, drivers should remember never to drive next to large vehicles in a roundabout.

This information is especially important with the new roundabout which is coming to Leesville, said Allen.