A 2.9-mile stretch of I-35 frontage road is being converted from two-way traffic to one-way.

On June 28, the frontage roads both east and west of the interstate, from Center Street in Kyle to Yarrington Road in San Marcos, will be converted from two-way lanes to one-way, southbound and northbound lanes.

The reason for the switch, which is expected to be completed on June 29, is twofold, said Mark Jones, Hays County Precinct 2 commissioner. Changing the frontage roads from two-way to one-way should improve mobility, and two-lane traffic on the roads caused safety concerns, leading to a number of serious accidents, he said.

"Two-way frontage roads have become more and more dangerous as we have gotten more traffic on that road," Jones said. "There is too much of a chance of a head-on collision."

The commissioner said accidents have been caused by motorists not yielding the right of way to vehicles coming down the exit ramp of the highway.

The county is trying to get the word out in advance of the switch to prevent confusion or any possible accidents. Jones said his office has sent out correspondence to a mailing list, posted updates on Facebook and informed visitors of the county website, among other methods.

"That's our biggest fear, is someone not knowing," Jones said. "We know we are not going to get everybody, but we are going to do the best we can to inform as many people as possible."

The commissioner advised drivers to be extra cautious as people get used to the changes.

The northbound frontage road will be the first to be worked on at 8 p.m. June 28, according to a Texas Department of Transportation news release. When work is done on that road, crews will begin working on the southbound frontage road. Additional signs will be placed along the highway to alert motorists to the changes.

"This is a very important safety project," said Ben Engelhardt, area engineer for TxDOT's South Travis Area Office, in a news release. "I-35 is the transportation backbone for the region and by switching these high-volume frontage roads to one-way, we hope to improve traffic movements in the area and ensure our system is as safe as possible."

As part of a broader, $12.2 million project, the Yarrington Road bridge overpass will be reconstructed, and turnaround bridges will be placed in the northbound and southbound directions.

Jones said the overpass had come to the end of its useful life.

"It's an older bridge," he said. "Its utility is not sufficient for the amount of traffic it has to handle each day."