MARTA's railcar rehabilitation program for improved reliability and better customer service

In 2003, the Metropolitan Atlanta Rapid Transit Authority (MARTA) embarked upon an ambitious program to modernize its rail car fleet. MARTA's analysis pointed to significant cost savings by having approximately two-thirds of their fleet rehabilitated rather than purchase new cars. That portion of their fleet is an average of 22 years old. Virtually all mechanical and electrical systems are being refurbished or replaced new, including HVAC, auxiliary electric, passenger doors, fault indicating and monitoring system, train network, cab controls and equipment, lighting, passenger communications and signage, friction brakes, and trucks. In addition to the challenges of refurbishing the cars, MARTA also required these refurbished cars to be operationally compatible with the other one-third of their fleet, which is an average of four years old. Beyond the basic operational compatibility of door control, propulsion, and braking, car systems such as on-board communications, passenger signage, fault and failure diagnostics systems were required to be compatible. Also, because of the high cost of replacement parts, MARTA encouraged as much interchangeability of parts as possible between the older fleet and the newer fleet. These various constraints on the railcar refurbishment design presented many challenges and uncovered some unexpected consequences that are discussed in this paper.