The Central Texas Regional Mobility Authority and the Texas Department of Transportation are partnering on the MoPac South Project designed to improve efficiency and travel times along the roadway.

The project would add two toll lanes in each direction on MoPac between Cesar Chavez Street and Slaughter Lane with an expected cost of $350 million, which does not include costs for noise walls, tolling components and construction oversight.

"We had to establish that there is a problem from Cesar Chavez to Slaughter regardless of any other projects that may be going on," said Melissa Hurst, Mobility Authority community outreach manager. "We looked at widening the lanes, high occupancy vehicle lanes, transit-only lanes, staggering traffic, ramp improvements and express lanes. They all helped, but express lanes were the best."

The project has moved to open houses at which the Mobility Authority is presenting the project to the public to receive feedback and adjust accordingly.

"When we met with residents in South Austin they were very concerned about the intersection at William Cannon [Drive]," Hurst said. "Originally, we didn't have anything planned for that intersection, but after hearing concerns we made some major changes there."

Proposed changes

The nearly 9-mile project would add two express tolled lanes in each direction from Slaughter Lane to Cesar Chavez Street on MoPac. The preliminarily plan would have entrances and exits to the express lanes between Slaughter and Davis lanes, between Davis and William Cannon, north of William Cannon and between Capital of Texas Hwy. and Bee Caves Road.

The express lanes would be positioned in the center of MoPac, except for the split on MoPac near the Capital of Texas Hwy. intersection, where the express lanes would divert to the east, along with the northbound traffic.

The other major split is at Lady Bird Lake, where the MoPac South project meets the MoPac Improvement Project to the north.

"The way it is set up is that drivers in the express lane heading north will be able to seamlessly continue on the express lanes from the MoPac [Improvement]Project under construction," said Jimmy Robertson, a representative with Jacobs Engineering, the firm developing the MoPac South Project.

Drivers on the toll lanes heading north on MoPac will take a flyover that will run from just north of Bee Caves Road to Cesar Chavez at Austin High School.

"The reason we are looking at a direct connection with downtown is that it is a heavily trafficked area," Robertson said. "We looked at the existing travel demand and the forecasted travel demand, and downtown is a significant attraction for trips. It is also where Capital Metro buses go, and we would like to see more transit in this area."

The proposed changes would also affect drivers headed southbound on MoPac who are looking to exit onto Bee Caves Road. The proposal would move the exit for Bee Caves Road about 500 feet north, allowing drivers more time to cross several lanes of traffic to head west on Bee Caves Road.

The city of Rollingwood met with the Mobility Authority along with Jacobs Engineering on March 11 to discuss concerns about how the city might utilize the express lanes, and traffic issues at the Bee Caves Road/MoPac intersection and the visibility of the flyover connection to downtown.

Rollingwood Mayor Thom Farrell said he is concerned about drivers who want to access the northbound express lanes from Capital of Texas Hwy. Hurst said the express lanes will be priced using the same structure as the MoPac Improvement Project to the north—a sliding scale starting at about 25 cents or 50 cents with no cap.

The rates increase when traffic is heavy and decrease when traffic is light, she said.

There will be signage at every entrance and exit noting the price, she said.

"It is not about collecting money," Hurst said. "It is about managing traffic flow. We want to price the tolled lanes so that those who take them can avoid the congestion."

Although the sliding scale rates have not been used in Austin, several such systems exist throughout the nation, Hurst said.

"When we were first looking at this, we looked at Houston, Atlanta and San Diego, all places that use this type of toll system, to try to learn all we could," she said.

Although the rates fluctuate, once a driver enters the express lanes, he or she pays that rate for the duration of his or her trip.

The tolled express lanes are designed to help alleviate traffic congestion on the roadway. According to a CDM-Smith 2014 study, peak traffic travel times from Cesar Chavez Street to Slaughter Lane are about 12-15 minutes. That is expected to increase to 45-47 minutes by 2035 if no improvements are made.

CDM-Smith is a consulting, engineering, construction and operations firm that focuses on water, environment and transportation issues.

The express lanes will also be available to mass-transit vehicles–buses and emergency service units.

"We hope [by allowing buses on the express lanes] it will also increase bus ridership," Hurst said.

Timeline

The project's environmental assessment, which began in April 2013, is expected to be complete in fall 2016 as long as it receives a Finding of No Significant Impact. After the study and public comment period concludes, Hurst said construction could begin by fall 2017 and take about three years.