Road Lock is a system whereby the GPS maintains your position icon "locked" to the road even when there are minor map errors or GPS position fix errors which would otherwise cause your position icon to be shown "off the roadway".
Units which offer "Road Lock"
Garmin
StreetPilot (all models)
GPS-V
GPS-76S
VISTA
LEGEND
eMap
GPS-176 (all models)
Note: Garmin models REQUIRE the use of MetroGuide or CityNavigator
or CitySelect for road lock to work. Road lock DOES NOT work on R&R
or TOPO maps.
Note: This is not an exhaustive listing. If you are aware
of other brands/models which offer ROAD LOCK, please email Joe Mehaffey