u.s. route 27 alternate (us 27 alt.) is a alternate route of us 27 that exists in the north-central part of the u.s. state of florida. it is signed north–south, but is a primarily east–west route, traveling between williston and perry. us 27 alt. is concurrent with us 19/us 98 from chiefland to perry, and also has the hidden fdot designation of state road 55 (sr 55). between williston and chiefland, it has the hidden sr 500 designation.