Drivers soon will see lowered speed limits on many of the most dangerous stretches of Austin's major corridors.

The Austin City Council approved reduced speed limits on eight roads, with more to come as part of a broad review of Austin streets and how growth has changed their use.

"We are trying to consider more characteristics and give a more comprehensive look, especially with increasing pedestrian activity and bicycles," Transportation Department Assistant Director Eric Bollich said.

Austin's speed limits were set decades ago based on Texas Department of Transportation and federal highway guidelines, which look mainly at the speed cars already are traveling to determine speed limits, Bollich said. Those guidelines don't take into account how the city has grown and changed over time, including the introduction of new transit types, like scooters.

So the city is conducting a holistic review of all of Austin's roads, looking at streets' characteristics, crash history and how many driveways people are pulling in and out of, as well as pedestrian and bus traffic. Previously, the department only had looked at lowering speed limits on residential streets.

The lower speed limits are still being added to the city code, and enforcement of the new speed limits won't start until new signs are posted. The changes include:

• Cameron Road from just north of U.S. 290 to U.S. 183 is reduced to 35 mph.

• Airport Boulevard from Interstate 35 North to Glissman Road is reduced to 40 mph.

• East Stassney Lane from Teri Road to just south of Burleson Road is reduced to 50 mph, and Stassney just south of Burleson Road to Burleson Road is down to 35 mph.

• Grove Boulevard from East Riverside Drive to Montopolis Drive is reduced to 35 mph.

• Montopolis Drive from East Riverside Drive to Burleson Road is reduced to 35 mph.

• South Lamar Boulevard from Barton Skyway to West Ben White Boulevard is reduced to 40 mph.

• Pleasant Valley Road from just south of Canterbury Street to Webberville Road and South Pleasant Valley Road from south of Canterbury Street to just north of East Oltorf Street are reduced to 35 mph.

• East Riverside Drive from just east of Crossing Place to just east of Vargas Drive is reduced to 35 mph and from just east of Vargas Drive to Texas 71 to 40 mph.

The corridors are all part of the city's high-injury crash network, where the most injuries and fatalities occur.

According to the Austin Transportation Department, 70% of the city's major crashes occur on only 8% of its roads.

Transportation safety officer Lewis Leff said speed was a contributing factor in a fourth of these crashes.

"The research all points to the fact that as speed limits go up, the chance of injuries goes up exponentially," Leff said. "If we want to see a change in our outcomes, we have to have a change in our behaviors. Every 5 miles per hour does make a difference in the outcome of a life versus a serious injury. That’s why we think it’s critical."

The city allocated $500,000 to the speed management program this year, including money to hire a new manager. Transportation officials said they expect to bring more packages of streets to the City Council to approve lower speed limits over the next year.

For those already approved, engineers will place new speed limit signs in the coming weeks. Leff said his office also has talked with the Austin Police Department and said officers will be leaning heavily on verbal warnings rather than issuing citations until people adjust to the new speed limits.