I-10W at Exit 269 / Wilmot Rd.
DPS will sit in a parking lot just north of the freeay and observe your speed as you go over Wilmot Rd. If they decide to get you, they jump right onto the on-ramp and catch up within a mile or so. Because this parking lot is below the freeway overpass, they are almost impossible to see – but they can still see you. Posted limit in this area is 65, but traffic frequently flows at ~75.