See also Van Alstyne… This construction zone is a nice revenue producer for these two cities. Construction is nearly done, yet the speed limit remains at 55mph. Howe, Van Alstyne, Grayson Co. Sheriff and DPS station themselves at the entrance and exit to the construction zone both North and South bound. Howe and Van Alstyne PD often sit at entrance ramps from thier respective towns. Enforcement seems to be heaviest between midnight and 4am.