Mail trucks are reportedly catching fire at an alarming rate

According to a MailTrucks. com report, roughly 120 mail trucks have caught fire in the past five years. The fires are not the result of accidents or crashes, but instead have been reported when the trucks are carrying out normal driving duties. The frequency of the fires has some worrying, but the U.S. Postal Service (USPS) continues to use the trucks on a daily basis.

While the USPS is gearing up to select its next-generation mail truck, the company currently uses Grumman Long Life Vehicles (LLVs). The Grumman's boxy straight-line design outlines the general U.S. public's perception of what a mail truck looks like, proof it's served duty for quite some time. But recently mail trucks have been seen in the news in drastically different settings. Around the country, LLVs have been engulfed in flames.

Thus far, the postal service has not found any specific cause of the fires. Trucks. com details parts of the investigation process:

• The Postal Service hired an engineering firm in 2014 to investigate the cause of the fires. When no single reason was discovered, the agency increased efforts to stick to mandated maintenance schedules and fine-tune repair and maintenance procedures, according to agency memos.

• The Postal Service declined to comment on the potential public safety hazard posed by the fires. It also declined to say how many fires have occurred. And it declined to comment on whether it has discussed the fires with Morgan Olson LLC, a successor company to the original manufacturer.

Although the causes are not known, reports have shown that the fires often start in or around the engine bay. The nose fires can then melt the truck body and eventually burn paper or other unknown material cargo. Refrigerated vans also catch fire easily. And it causes a major loss to cargo and vehicle.