Recent modifications at both traffic roundabouts on Main Street at Cemetery and Scioto Darby roads in Hilliard essentially are complete, deputy city engineer Letty Schamp said Aug. 19.

Work began June 3, she said.

The roundabout improvements are meant to slow vehicle speed at the entry and exit points of the roundabouts, make pedestrian crossings safer and reduce the number of minor vehicle accidents, said Hilliard service director Albert Iosue.

The modifications include the placement of signs with red LEDs in the center island of the roundabout at Main Street and Cemetery Road, with one facing each of the four approaches, Schamp said.

Raised crosswalks, resurfacing and overhead lane-control signs also were part of the modifications. Resurfacing allows for better visibility of new pavement markings, Schamp said, while raised crosswalks will slow vehicle speeds and increase pedestrian safety.

New signs and markings are meant to provide drivers with a better understanding of how to navigate a two-lane roundabout, she said.

Meanwhile, at Main Street and Scioto Darby Road, the roundabout has been reshaped.

"The crash pattern at this intersection was due to the skewed intersection angle and irregular exit geometry," Schamp said.

In an effort to "reshape" the roundabout at Main Street and Scioto Darby Road into more of a circle than an oval, temporary curbs were built within the roundabout, Schamp said.

At an uncertain future time, and after it is determined the temporary curbs are in the preferred location, permanent curbs would be placed, she said.

In March, Hilliard City Council approved a contract with Strawser Paving Co. for $544,000 to make modifications to both roundabouts.

The modifications were made in reaction to the number of accidents that continued to occur at each roundabout.

Although a slight increase in minor accidents was anticipated after the Main Street roundabouts opened in 2011, those figures did not decrease as expected, Schamp said.

A report from the Mid-Ohio Regional Planning Commission released in 2016 said the roundabout at Main Street and Cemetery Road had the most reported accidents in Hilliard, 233, from 2013 through 2015.

It was followed by Main Street and Scioto Darby Road, with 141 reported accidents in the same three-year span.

Documented crashes also were numerous in the years after the study.

According to the MORPC website, the Main and Cemetery roundabouts had 81 reported crashes in 2016 and 98 in 2017. The Main and Scioto Darby roundabout had 38 reported crashes in 2016 and 47 in 2017, the website said.

Based on the 2016 report, City Council in 2017 approved a $160,000 contract with Burgess & Niple, the same firm that engineered the roundabouts, to find ways to modify them to reduce the frequency of accidents, resulting in the contract with Strawser Paving Co.

Moving forward, the city's engineering department will collect "after" data beginning Monday, Aug. 26, and compare it to data collected in April "to evaluate the effectiveness of the raised crosswalks and to help inform best practices in the future," Schamp said.

Crash-report views and capacity reviews also will be conducted, she said.

Next year, crash data from 2019 will be used to determine the effectiveness of the modifications and the city's outreach campaign on roundabouts, Schamp said.