Travelling southbound, Flood Ave. begins as an exit off of I-35 south with only a few traffic lights between the ramp and Rock Creek. If the lights are aligned, the tendency is to maintain highway speeds all the way. At Rock Creek, the limit suddenly changes to 45, that is where the radar is. If not there, they are frequently sitting one light further south at Lexington or Westheimer where the limit is reduced to 35 mph.