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Highway 17: Engineer’s review finds fewer crashes in median project area
By Charles Swenson
Out of 200 accidents, a traffic engineer hired by opponents of a median project on Highway 17 in Pawleys Island, said this week he only identified about 90 that are related to the configuration of the roadway.
“We looked at four and a half years of crash data. It was pretty consistent: 20 to 30 crashes a year in the corridor. I don’t think that’s outrageous,” said Eric Tripi, the director of operations in South Carolina for Iteris, a global traffic management firm.
Tripi was hired by the Citizens Coalition for Ocean Highway to review state accident data for 1.8 miles of Highway 17 from Waverly Road to Baskervill Drive where the state Department of Transportation plans to install a raised median in place of the paved median. Opposition to the project is led by business owners who believe the restrictions on left turns that are part of the median project will impact their customers. The coalition has also challenged the safety of the project.
DOT said the project will improve the flow of traffic through Pawleys Island, improve safety and look better than the paved median. At public meetings on the project in early 2012, DOT staff said there was an average of 3.4 crashes a month in the project area, twice the rate for similar roads.
“We were never able to get information from DOT about similar roads,” Tripi said. “That was a flag that there are some things in here we can take a look at.”
Opponents also questioned the use of data for accidents that occurred south of the Waverly Road intersection by DOT’s consultants.
The coalition obtained accident information from the state Office of Highway Safety. The data is contained in spreadsheets that list accident times, locations and causes, among other things. That was the same data used by the engineering firm hired by DOT to plan the project, said Mark Hoeweler, the senior staff member for the Grand Strand Area Transportation Study, which approved funding for the $3.75 million project.
The level of review was appropriate for the project, he said. “It’s a cross-section of the road.”
The coalition used the spreadsheet data to request Highway Patrol incident reports for 207 accidents. “They tell you a lot more than the spreadsheet,” Tripi said. “The officer actually has to draw out a diagram.”
Although the spreadsheets include GPS data for the accidents, the information isn’t always accurate because of the way the equipment is used.
Since 2011, the Highway Patrol has been using GPS mapping linked to computers in patrol cars. But even that doesn’t have the detail of a state trooper’s report.
“Sometimes it may look like a crash occurs because of the geometry of the road,” Tripi said. “Sometimes you can find out what the real cause of the accident was.”
He doesn’t fault the work of the DOT consultants. “All we did was dig a little deeper,” he said. “The data didn’t bear out that the road conditions were causing a majority of crashes.”
Most of the accidents in the median project area occur at the two traffic signals: Waverly Road/North Causeway and Martin Luther King Road.
Tripi ruled out some of the accidents that occurred at the intersections, such as those where a vehicle heading south was involved in a rear-end collision. That situation wouldn’t change under the proposed median project.
He was particularly interested in finding accidents that occurred when vehicles were turning left out of driveways and side streets.
“If there’s a large number of left turns from driveways, I could get on board with that,” Tripi said.
Studies show that medians such as the one proposed for the Pawleys Island area tend to reduce accidents.
But, Tripi said, “I don’t see that pattern here. Do they really need this?”
He hasn’t prepared his final report to the coalition, but the group has already proposed maintaining sections of the paved median while installing landscaped medians in between.
“I think you can consolidate a few driveways and create strategic locations where you have a median and a median cut,” Tripi said. “You don’t have to median the whole thing.”
Another thing Tripi found in the reports was a large number of crashes with drivers in their 80s. “A younger driver may not have made the errors,” he said.