The United State Postal Service lacks the resources to modernize its aging fleet of delivery vehicles by replacing the vehicles or adding technology such as GPS tracking, according to a report by the Office of the Inspector General.

During fiscal year 2012, the USPS spent more than $906 million on maintenance for its fleet of nearly 212,000 vehicles that is one of the largest in the country. About 75% are Grumman LLVs (long-life vehicles) that have a 24-year lifespan. Some of the LLVs have been in use for as many as three years beyond that.

By using fleetwide GPS tracking, the agency could gain a better understanding about how the vehicles are being used, which could extend their lifespan.

The USPS developed a fleet replacement plan in 2011 that called for acquiring 25,000 vehicles at a cost of $500 million starting in fiscal-year 2017. The plan lacked details such as vehicle specifications and was never implemented, according to the OIG.

Earlier this year, the USPS received approval to purchase 3,509 vehicles to meet a contractual rural carrier vehicle committment.

The OIG urged the USPS to continue acquiring vehicles in the short term and formalize a long-term plan to replace the fleet with specifications for the next generation of delivery vehicles.

Read the full report here.