Update on the MoPac Intersections – Slaughter Lane & La Crosse Ave

Exciting news! The project team continues to reach milestones on the MoPac Intersections project. The diverging diamond intersection (DDI) at Slaughter Lane opened in October and you’ve probably noticed traffic flow has greatly improved. Crews are also working on the Slaughter Lane ramps and overhead sign bridges at the DDI to install permanent signage.

Construction is moving south toward La Crosse Avenue. Sound walls are being built on the east and west side of MoPac between Slaughter Creek and La Crosse Avenue. Retaining walls are being erected in various locations, and excavation activities continue to prepare for bridge construction, which is anticipated to begin this spring. The project remains on time for a completion date of early 2021.

Throughout the construction process crews have discovered some interesting features in the area, which are common in the Edwards Aquifer Recharge Zone. Examples of these karst features include underground caves, sink holes, fractures and voids. The end result can be intriguing and we wanted to share some photos with you.

While these voids can be fascinating and tempting to explore, we ask that the public steer clear for their own safety. Our geoscientists are currently mapping the features and determining the next course of action. TxDOT is also working with the Texas Commission on Environmental Quality, the City of Austin and the Barton Springs Edwards Aquifer Conservation District to evaluate and put mitigation plans together, so that we can continue building the MoPac mainlanes under La Crosse Avenue, while protecting the aquifer.

Regular updates are shared via email and Twitter. To sign up, please send an email to MoPacIntersections@txdot.gov with “updates” in the subject line, or follow us on Twitter @TxDOTAustin, search #MoPacIntersections.


MoPac Intersections Project Team
(512) 693-7425

Below is a diagram showing the configuration and how to drive through it.


General Construction Information

Please note that schedules are subject to change due to weather or field conditions. General work hours take place Sunday through Friday. Work will occur both during the day and at night during the times shown below, unless otherwise noted.

Daytime Work Hours: 7 a.m. to 6 p.m.
Nighttime Work Hours: 7 p.m. to 6 a.m.


Alternating north and southbound lane closures continue nightly from South Bay Lane to Davis Lane.

Sunday – Thursday, 8 p.m. – 6 a.m.
Friday – Saturday, 10 p.m. – 8 a.m.


Alternating east and westbound lane closures continue nightly at the MoPac intersection.

Sunday – Thursday, 9 p.m. – 5:30 a.m.
Friday – Saturday, 10:30 p.m. – 8 a.m.