An army is only as effective as its mobility, so the Grand Army of the Republic was outfitted with an increasingly varied and versatile vehicle pool as the Clone Wars progressed. The BARC speeder gave a single clone trooper increased operational range, great speed, mobility, and firepower otherwise unavailable to the foot soldier. A more aggressive and bulkier design than slimmer speeder bikes used by the Jedi, the BARC speeder was used in scouting and escort missions on a variety of worlds. They were easily adaptable, with support struts that could be added to hold a stretcher or sidecar.
Anakin Skywalker has a talent for mastering any kind of high performance craft. With a top speed exceeding 500 kilometers per hour, the BARC speeder met Anakin's standards for velocity.
Most clone ground troops receive training on low-altitude repulsorcraft like the BARC speeder. Clone Captain Rex's squads of clone troopers were effective as mounted infantry -- a quality that saved his life when his troops needed to rush him to safety aboard a BARC speeder after suffering injuries while on Saleucami.
Ahsoka Tano served as Anakin Skywalker's gunner in an articulated sidecar attached to his BARC speeder while investigating the vanished colony on Kiros.
The automated police forces on Coruscant employ a model of BARC speeders to patrol the skylanes of the capital city.