The Coastal Conservation League asked Gov. Nikki Haley Thursday to prevent the state Department of Transportation from cutting down the trees in the Interstate 26 median from Summerville to Interstate 95.

The $5 million DOT project aims to reduce fatalities and severe-injury crashes. It is part of a plan to widen the interstate to three lanes in each direction. Cable guardrail would be installed in the middle of the median after the trees are removed.

In a letter dated Thursday, a law firm representing the league wrote, “Please require SCDOT to consider all feasible and reasonable alternatives in their project planning process before they implement this costly and unjustified plan.”

Highway Commissioner Jim Rozier of Moncks Corner said he supported leaving the wetlands and hardwoods in the median, but removing pines. The interstate passes over Four Holes Swamp, he said.

“There are a lot of wetlands,” Rozier said.

Dana Beach, executive director of the Coastal Conservation League, said he supported a thorough environmental analysis of the situation.

“They don’t have to cut all the trees down to provide the safety improvements they want to provide,” he said.

Haley spokesman Rob Godfrey said in an e-mailed statement, “It is our understanding that SCDOT thoroughly weighed the safety concerns and high number of fatalities in that stretch of I-26 along with all options to preserve trees in that dangerous area, and concluded that safety of drivers had to remain their highest priority.”

DOT spokesman Pete Poore had no response to the league request.

In its letter, the league suggests alternatives, such as rumble strips on the paved shoulder, selectively clearing trees within 30 feet of the roadway, reducing the speed limit from 70 mph to 60 mph or 65 mph, and increasing law enforcement.

It is in the best interest of the state and DOT to demonstrate that safer conditions on I-26 require removing the trees on 30 miles of interstate, the letter states.

“SCDOT has so far failed to do this,” according to the letter from Leath, Bouch & Seekings LLP.

Clearing every tree from the median and installing a cable down the center of the median will cause the greatest possible environmental and aestheic impact to the project area, the letter states.

“SCDOT has failed to show that any other reasonable alternatives that may be less costly and/or less impactful have been seriously considered,” the letter states.

The DOT is in the process of preparing a contract for the I-26 project, which will require an environmental permit from the Army Corps of Engineers. The work, which could begin in the fall, will take about a year to complete, officials said.

The trees in the median are primarily pines, with some hardwoods, DOT said.

I-26 in the project area has an annual average daily traffic count of 32,433 vehicles. From 2007 through 2011, 1,934 crashes resulting in 44 fatalities and 709 injuries occurred in the stretch of interstate. Half of the crashes were run-off-the-road accidents, the DOT said.

The crash causes were primarily distracted drivers and drivers who fell asleep.

Other factors were DUI, speeding, driving too fast for conditions, tire failure, improper lane change and debris in the roadway, the DOT reported.

When the project is finished, the zone where drivers can recover from running off the road into the median will grow from 25 feet wide to 46 feet wide on both sides of the interstate, the DOT said.