INDIANAPOLIS -- A truck driver who flipped a liquid propane tanker on Indianapolis' northeast side Thursday, causing a massive explosion and fire that forced the closure of interstates 465 and 69, has received two citations stemming from the incident.

Ronald Tobias, 73, was cited for an unsafe lane change and for driving too fast, 6News' Rick Hightower reported.

Indiana State Police said they have not charged Tobias and that he will not lose his license, but the investigation, which also involves the National Transportation Safety Board, is continuing.

"Everything points to this being an issue of driver error, and that's based upon people that witnessed the crash, as far as how they discussed how he was driving right before the crash occurred," said ISP 1st Sgt. Dave Bursten.

The maximum fine for each citation is $500, but police said Tobias or his company could face insurance costs for repairs and damage to the highway, which will easily be more than $1 million.

The ramp from southbound I-69 to southbound I-465, the last remaining closure because of the incident, reopened Tuesday morning.

Extensive testing over the weekend indicated that the steel bridges that were charred by the explosion and fire are structurally sound.

"We've brought in a number of different experts to provide second and third opinions, and we've done a number of different retests," said Indiana Department of Transportation spokesman Will Wingfield.

Traffic flowed smoothly Monday on I-465 after all eastbound lanes were reopened, and motorists were relieved that the possibility of weeks or months of detours had not come to fruition.

"It's probably costing me about 15 minutes or so," said one motorist, referring to the ramp closure.

INDOT said it will station signal technicians at detour intersections until the ramp is reopened to ensure that traffic doesn't back up too much.