At 1015 hours stations 10 & 11 were dispatched to Rt 222 NB by Rt 61 in Muhlenberg Twp for a reported TT on fire. Chief 10 arrived on Rt 222 NB in Ontelaunee Twp with a fully involved cab from a tractor trailer and a large area of grass was on fire and spreading. Stations 37 & 12 were added to the assignment. E11 arrived and deployed 2 attack lines and went in service. E12 arrived and also stretched a line. The fire was contained and the crews overhauled the truck.