A full-scale circulator system that will carry Tysons Corner commuters from Metro to their jobs won’t be in place by 2013, Fairfax County officials acknowledge.

The large-scale bus or shuttle system is a key ingredient in lofty plans to remodel Tysons as a pedestrian-friendly cityscape. But officials and county staff are publicly curbing expectations for the transit system, which remains unfunded, instead pitching a scaled-back bus network to coincide with the opening of four new rail stations in 2013.