Usually a marked Garland PD cruiser with or w/o light bar will sit off the right shoulder in the grassy knoll on I-30 Eastbound just past the Rose Hill overpass before the Bobtown exit. Also a Garland PD unit will stake out the grassy area just past the Northwest Dr Eastbound on-ramp behind the concrete retainer wall before the Beltline exit. On the actual bridges that cross Lake Ray Hubbard (Dallas County) it has been noticed a full size Dallas PD white Ford F-250 4×4 with full light bars will have vehicles pulled over as he does have jurisdiction on the lake.