[4] The SLRVs were designed to both increase passenger capacity and to improve the accessibility of DART's light rail system.

Thus, DART began to add a third section to go between the end cars, with low floor boarding and spots for wheelchair users.

Working in partnership, DART and Kinki Sharyo created the SLRVs by separating the existing two-section LRVs at their articulation joints and inserting an entirely new section in between,[3][8] thereby rendering them three-section vehicles.

[1][3] The middle section, variously called "Body C",[4] "C Unit", or "C Car",[10] has a low floor and provides step-free access to the SLRV.

[3][8] G. James Morgan of LTK Engineering Services estimated that DART saved over $50 million by converting its LRVs instead of buying new accessible vehicles.

Originally, SLRVs used a rollsign to display the destination, however the barcodes and the scanner would become dirty and would not read the sign correctly, causing them to get stuck in the wrong position.