This from a communication from the office of City of Austin Transportation Department:

New traffic calming project installed in District 7

The Austin Transportation Department (ATD) began installing speed mitigation devices on Rockwood Lane between Primrose Lane and Steck Avenue on Feb. 16, 2016. The project is part of the Local Area Traffic Management (LATM) program, a community-request driven program which aims to enhance safety by addressing a documented speeding issue on neighborhood roads.

Following approval of the Rockwood project through the LATM process, ATD completed installation of four sets of pre-fabricated rubber speed cushions as the first phase of the traffic calming project on Feb. 16. These cushions have been strategically placed so that passenger vehicles are required to slow down while still allowing emergency vehicles to straddle the devices without affecting response times.

In the next phase a traffic circle will be installed at the intersection of Rockwood Lane and Stillwood Lane.  Traffic circles have been proven to reduce speeding and increase driver awareness, two things that will help enhance roadway safety for the neighborhood residents and families attending Pillow Elementary School. ATD anticipates construction of the traffic circle to begin later this year.

Residents along Rockwood Lane submitted an LATM program application in 2012. As part of the approval process ATD completed a speed study in the area and during a 24-hour period documented more than 320 instances of vehicles traveling more than 35 miles per hour (mph) in the 30 mph zone.