DART discusses updates and mitigations in Cotton Belt Corridor Project


By Ariel Graham | DFW Newsflash | December 2017

Dallas Area Rapid Transit (DART) hosted an open house meeting to discuss the latest developments with the Cotton Belt Regional Rail Corridor Project at Parkhill Junior High School in Dallas on Wednesday, Nov. 29.

The Cotton Belt corridor is a proposed 26-mile light rail line, which will extend from Dallas-Fort Worth International Airport to Plano, and pass go through Plano, Richardson, Dallas, Addison, Carrollton, Grapevine and Coppell. The corridor will also connect with three existing DART light rail lines: the Red Line in Richardson, the Green Line in Carrollton, and the Orange Line at DFW Airport. According to DART, the Cotton Belt corridor is designed to improve mobility and accessibility for passengers in the northern part of DART’s service area. Currently, the corridor is expected to be completed by the end of 2022.

Wednesday night’s meeting primarily focused on the various impacts the corridor will have in residential and commercial areas, as well as a number of mitigations DART plans to use to offset these impacts. John Hoppie, one of the project managers for the Cotton Belt corridor, led the discussion. One of the primary concerns citizens have concerning the corridor are the noise levels and the vibrations caused by the train.

According to Hoppie, DART plans to employ two different types of mitigation to reduce the noise caused by the Cotton Belt corridor trains. DART would be implement ‘quiet zones’ in residential areas where the train would not be allowed to sound its horn, which is the primary cause of noise impacts.


“We had 5,419 noise impacts without quiet zones, and that’s just from the train horn,” Hoppie said. “With the quiet zones, and that’s with putting in additional safeguards at crossings and eliminating the train horn, it eliminated all of the severe and most of the moderate impacts. Overall, 96 percent of noise impacts are eliminated by using quiet zones.”

The second mitigation option is to build construction sound barriers, 12 to 15-foot tall walls along the tracks that would absorb much of the sound coming from the rails.

As far as vibration impact, Hoppie explained that DART would be using Tire Derived Aggregate (TDA), in the ballasts (the stone used to form the bed of a railroad track) underneath the tracks at seven different points where the vibration is the most notable.

“We are going to be proposing for all of the vibration impacts Tire Dervied Aggregate,” Hoppie said. “We put in a base of the Tire Derived Aggregate, which is basically chopped-up tires and rubber, underneath the sub-ballast. Then you put in ballast, and then you put in your tracks. It is very effective in reducing vibration.”

Throughout the meeting, Hoppie stressed the information presented was not finalized and all of the mitigations and recommendations are still subject to approval from the DART Board. Still, during the question and answer segment, many citizens expressed frustration at the lack of ‘concrete numbers.’ Chad Edwards, assistant vice president of capital planning, explained information would not be finalized until the Environmental Impact statement is available early next year.

“There will be ‘finalized’ information in the Environmental Impact statement, so you will be able to see where everything is, what it looks like, how it’s going in, in the environmental document,” Edwards said. “That’s what we’re working toward with all of this effort here.”

Tim McKay, executive vice president of growth and regional development, added the Cotton Belt corridor is still in its very early stages of development, and DART will continue to seek input from the community during the design process.

“We are at 10 percent level of design,” McKay said. “This is just the beginning, so we’re putting big blocks into place. Part of the frustration is people asking, ‘When are we going to stake this into the ground?’ So, after the environmental draft, what happens next is we are going to continue finalizing the design and we are going to continue to have input from the community.”

DART conducted a second public meeting Thursday, Nov.30 in Richardson. The next public meeting will be held Thursday, Dec. 7 at 6:30 p.m. at the Addison Conference Centre.