While going to check on a small fuel spill reported to be the ramp from I70-eb to I270-sb, Chief 3-C encountered what appeared to be significant smoke in the median of Rt. 15/340 eb/nb. Chief 3-C called in the collision with vehicle on fire, eastbound just east of Jefferson Technology Blvd. Bystanders attempting to extinguish the fire with portable extinguishers however, the vehicle continued to remain on fire and grow in intensity. ECC dispatching PE311, E72, RS3, A19, A318, ALS4, BC903, and EMS900 for the vehicle collision with rollover, vehicle on fire. Chief 3-C controlling traffic on Rt. 340-eb as units approached, some utilizing Jefferson Technology Blvd. and backing up to incident on the eastbound side. PE311 stopping on the westbound side and crew deploying hardline to extinguish the fire. EMS crew assessing subjects from the vehicle on fire as well as the tractor trailer involved. Chief 3-C holding units on the scene, no entrapment and possibly patient refusal(s). MSP and SHA arrived and handling traffic control and retaining the incident scene as Chief 3-C cleared the remaining units upon determination of fire out.