How many lanes should there be? How should the lanes be divided? What are environmental concerns? Is lighting an option? How much room is available for a pathway? Where should turn lanes be included?

Those are a few of the questions officials working on an Alaska Department of Transportation and Public Facilities Sterling Highway Safety Corridor Study are working to answer.

And DOT&PF is looking to the public for feedback to help select the best option to increase safety and mobility to the 11.5-mile stretch of highway between Soldotna and Sterling.

At meetings in Soldotna and Sterling this week DOT&PF shared its Decision Document for the Sterling Highway Safety Corridor Study, which explores highway lane alternatives between Mile 82.5 and Mile 94.

“The document will stay in draft form until after the meeting(s) and depending on what we hear, we may make some changes,” said Anne Brooks, public involvement coordinator.

The department also identified its preferred option and ruled out two alternatives for road construction.

Aside from doing nothing, the document identifies five alternatives for the highway:

A) 4-lane divided with a 30-foot depressed median;

B) 4-lane divided with two-way left-turn lane or raised median;

C) 2-lane divided with 30-foot depressed median;

D) 2-lane divided with 30-foot depressed median with alternating passing lanes;

E) 4-lane divided with a 2-foot concrete barrier.

DOT&PF evaluated the designs on safety, traffic capacity, mobility, engineering, maintenance and operations, land use, environmental resources, pedestrian and bicycle accommodation and cost. In each category, the alternatives were ranked most favorable, less favorable or least favorable.

Officials have ruled out alternatives C and D because they don’t meet the purpose and need.

Alternative A has been identified as the preferred option and B and E could be used in select areas.

The 4-lane highway divided with a depressed median had five most favorable marks — the most of any alternative. It ranked high in safety, capacity, mobility, maintenance and operations and land use. The alternative calls for two 12-foot travel lands in each direction, 8-foot outside shoulders, 4-foot inside shoulders and a 30-foot depressed center median. It was the only category to receive no least favorable marks.

Dennis Linnell, project manager, Hattenburg, Dilley and Linnell, LLC, said members of the public have commented that they would like to see a pathway along the highway. Alternative A takes up a large amount of right-of-way making it difficult to construct a path with optimum separation from the road of at least 22 feet along the entire stretch of highway.

If a path is constructed, he said in areas where optimum separation is possible, that’s what DOT&PF would do and in areas where the path would be close to the road, a guardrail would likely be installed.

Linnell said one of the biggest challenges with the project is figuring out how to balance two competing needs —mobility and access to residences and businesses.

Keith Baxter, Soldotna City Council member, attended the meeting in Soldotna on Tuesday and said with the highway serving local and through-traffic, he is glad to hear DOT&PF is considering both sides.

According to DOT&PF, the 11.5 miles of highway is over capacity and has a high rate of fatal and major injury crashes.

Moose-involved collisions accounted for 28 percent of crashes between the Kenai Spur Highway and Moose River from 2000 to 2010, with 80 percent of those crashes happening at night. Twenty-seven percent of crashes were rear-end collisions. Compared to statewide averages, running off the road, head-on and sideswipe collisions are overrepresented. Nearly 75 percent of crashes happened between October and March during twilight or after dark.

Rear-end and right-angle crashes occurred at a slightly higher rate, 55 percent, between April and September. This data corresponds with higher traffic volumes.

The highest crash areas were at Robinson Loop Road to Murray Lane, the Forest Lane and Jim Dahler Road intersection to Boundary Street, Boundary Street to Mackey Lake Road and Mackey Lake Road to Devin Drive.

The next step in the process is the preliminary engineering study, which Brooks said gets into detail about right-of-way, access points and drainage issues. The process for the engineering study will being in July and wrap up in the first quarter of 2015, she said.

In December 2013 DOT&PF held a public meeting about the project. Locals at the meeting expressed concerns about moose mitigation, the amount of traffic, drivers speeding and accessibility to businesses along the highway.

DOT&PF also held mobile meetings in parking lots in Soldotna and Sterling last summer for local citizens to discuss the safety corridor.

Linnell said most commenters have been supportive of the project.

“Everybody knows something needs to be done,” he said.

To view the document and other information and submit comments about the project visit www.sterlinghwy.com.

Kaylee Osowski can be reached at kaylee.osowski@peninsulaclarion.com.