Manteca leaders hinted they might resort to roundabouts and other traffic calming devices on Cottage Avenue and Crom Street after increasing speed limits on those streets to conform to state mandated rules involving issuing tickets using radar.Council members Debby Moorhead and Steve DeBrum were on the losing end of a vote Tuesday night that certified higher speeds on 28 segments of streets to allow Manteca Police to continue using radar for speed enforcement. They blasted the state rules as being “wrong” and counter to efforts to make streets safer.Both indicated they wanted to see the city come up with ways to slow down traffic on the two streets as well as Button Avenue.Every seven years jurisdictions that use radar to enforce speed on city and county streets must do a traffic survey using radar to record the speed of all vehicles driving streets during a set period where radar is used. Essentially, speed is adjusted to what the 85th percentile of traffic is traveling.“It seems if we have speeding we have to raise the speed limit,” said Councilman John Harris who said he reluctantly was supporting the new speeds.