City of Oakland Public Works Department addressed this issue on 07/02/2014, service request # 486102.

This is getting worse. Too many speeders & accidents. Also note that the Beacon School is right next to Kennedy Street. Very dangerous. Coming off the 880 South Freeway - No one see's the very small 30 MPH solo sign. Most of the time it is blocked by parked trucks. A larger sign and additional signage along Kennedy Street is a must...

The City of Oakland Public Works Department has received this issue. It is registered as service request # 528222. Please check back for status updates or contact us directly at (510) 615-5566.

An additional sign was recently installed (30 Zone Ahead) just after the 880 offramp and before the 30 speed limit sign. We'll see if it helps slow the traffic at all.