AUSTIN (KXAN) — With the construction of the 183 and 45SW toll roads, drivers have new speed limits they’ll need to heed.

On Monday, members of the Central Texas Regional Mobility Authority approved maximum speed limits for both toll roads. Board members approved capping the legal speeds at 75 miles per hour for 183 and 70 miles per hour for 45SW.

Engineers took into consideration crash and fatality rates along CTRMA roadways when compared to statewide averages and conducted speed limit studies along both tolls. For average crash and fatality rates, these were broken down by roadway classification — either an urban U.S. highway (such as U.S. 183) or an urban state highway (like SH 71).

CTRMA-managed road 183A had a 2020 crash rate of 26 per 100 mile millions traveled, while 290E had one of 49 per 100 million miles traveled. Comparatively, the 2020 state average was 169 per 100 million miles traveled.

For urban state highways, CTRMA-managed roads include SH 71, MoPac Expressway and 45SW. Those 2020 crash rates were as follows:

  • SH 71 Toll: 25 per 100 million miles traveled
  • MoPac EL: 88 per 100 million miles traveled
  • 45SW: 27 per 100 million miles traveled

At the state level, its 2020 average was 169 per 100 million miles traveled.

In a 183S speed study, CTRMA engineers observed the average speed for northbound drivers was 72 miles per hour, while southbound drivers clocked in at 75 miles per hour. With the 45SW speed study, the findings reported a northbound average speed of 70 miles per hour and southbound speed of 68 miles per hour.

Prior to the vote, board member Jay Blazek Crossley said he’s happy several studies and factors were taken into consideration during this analysis, particularly because speed is the largest contributing factor to crashes in Texas.

He added while these are proactive measures already in place, he’d like to see CTRMA adopt a Vision Zero-like program akin to other regional or state agencies to make ending traffic deaths an expressed goal.

“I do think that this is a fluid conversation,” CTRMA Board Chairman Bobby Jenkins said, adding speed limit studies are a “moving target” and need continuous monitoring.