Truck collisions and near-collisions are low from January through June, but more than triple at points between July and November, according to a new analysis of truck crash data.

Also, collisions and near collisions peak on Tuesdays and Fridays in the long-haul trucking segment, peaking between 3 p.m. and 4 p.m. as well as 8 p.m. and 9 p.m., with crash levels dropping to their lowest levels between 11 p.m. and 9 a.m.

These are the findings of California-based DriveCam Inc., which analyzed its video event recorder database of over 18-million driving events across two-billion driving miles accumulated during 2009 to examine the frequency of collisions and near collisions by month, day, and time of day.

DriveCam’s research found that collisions and near collisions in long-haul trucking are very low from January to June (between 1% and 5%), but start to spike in July, peaking at 18% and remaining above 14% through November.

On average, DriveCam found the collision/near collision rate in long-haul trucking is, on average, over 5% higher than other Industries – specifically construction, distribution, energy, waste, telecommunications, local distribution and transit – from June to November.

Collisions/near collisions peak on Tuesdays and Fridays in long-haul trucking (21% and 20%, respectively), with the long-haul sector’s crash rate comes in slightly lower than the other industries noted above on Wednesday and Thursday, as well as on Saturday and Sunday.

By hour of the day, the collision/near collision rate in long-haul trucking remains below 4% from 11 p.m. until 9 a.m. Beginning at 9 a.m., however, the collision rate begins to climb, taking a small dip between 1 p.m. and 2 p.m. before increasingly sharply to peak at 9% between the 3 p.m. and 4 p.m. The crash rate then takes a sharp nosedive before rising to 6.5% between 8 p.m. and 9 p.m. before starting a decline to around 4%, DriveCam noted.

“Crash statistics don’t lie. It makes sense that driving gets riskier as the day goes on,” David Kelly, former Acting Administrator of the National Highway Traffic Safety Administration (NHTSA) and now president of consulting firm Storm King Strategies, told FleetOwner.

“For example, people aren’t generally getting drunk in a bar in the morning,” he said. “While it happens, it is much more predominant at night. People are also getting more tired as the day progresses. Visibility is also more of an issue as it gets darker.”