Following-Distance & Headlight Rules, by state.
How far back to follow another vehicle, when to dim high beams for oncoming and following traffic, and the move-over law for emergency vehicles.
| State | Following Distance Rule | Headlight Dim Oncoming Ft | Headlight Dim Following Ft | Headlight Law | Emergency Vehicle Min Following Ft | Motorcycle Following Rule | Cyclist Safe Passing Rule | Move Over Law | Defensive Driving Framework |
|---|---|---|---|---|---|---|---|---|---|
| Colorado | Use the three-second rule in normal conditions: watch the vehicle ahead pass a f... | 500 | 200 | Colorado law requires headlights to be on from sunset to sunrise and whenever vi... | – | The Colorado Driver Handbook does not give a numeric following distance specific... | Colorado requires drivers to give bicyclists a minimum of three feet of clearanc... | When approaching a stopped emergency vehicle displaying flashing red, blue, whit... | none |
| Illinois | Use the three-second rule: pick a fixed object on the road ahead such as a sign,... | 500 | 300 | Headlights must be on from sunset to sunrise. Illinois also requires headlights... | – | Allow at least three to four seconds of following distance when you are behind a... | When you pass a bicyclist on any Illinois road, including in a marked bike lane... | When approaching a stationary emergency, police, or maintenance vehicle that has... | – |
| Nevada | At 40 mph or less, stay at least two seconds behind the vehicle ahead. The two-s... | 500 | 300 | Headlights are legally required from a half hour after sunset until a half hour... | – | Nevada's manual does not give a specific car-length or second count for followin... | When passing a cyclist on a road with more than one lane in the same direction,... | When approaching any vehicle stopped on the roadway and displaying flashing emer... | – |
| Oregon | 2 to 4 seconds; 4 or more seconds above 30 mph | 500 | 350 | Headlights required from sunset to sunrise and any time you cannot see people or vehicles 1,000 feet ahead; dim high beams within 500 ft of an oncoming vehicle and within 350 ft when following. | 500 | More distance than for a car | At speeds over 35 mph: enough distance to prevent contact if the cyclist were to fall | Oregon's move-over law applies to **any motor vehicle stopped with lights flashi... | Oregon names no defensive-driving framework; the manual never uses SIPDE, IPDE, or the Smith System; it teaches narrative guidance instead. |
| Pennsylvania | Pennsylvania uses a 4-second following distance on dry highways. To check it, wa... | 500 | 300 | Pennsylvania law requires drivers to use their headlights between sunset and sun... | 500 | Leave three or four seconds when following a motorcycle, so the motorcyclist has... | Pennsylvania law requires drivers to allow at least four feet between the vehicl... | Pennsylvania's Move Over Law requires drivers to move into a lane that is not ad... | – |
| South Carolina | Keep a minimum four-second following distance between your vehicle and the vehic... | 500 | 200 | Turn on your headlights during rain, snow, or fog (use low beams to cut glare),... | – | When following a motorcyclist, keep a minimum four-second following distance, an... | South Carolina's manual instructs drivers to slow down and allow as much space a... | When you approach a stopped authorized emergency vehicle with its lights flashin... | – |
| Virginia | Virginia teaches a two-, three-, four-second rule that scales with speed: at lea... | 500 | 200 | You must use your headlights in Virginia from sunset to sunrise, and any time in... | 500 | Never tailgate a motorcycle. Virginia's manual says to add an extra second to th... | Virginia requires motorists to pass cyclists with at least three feet of clearan... | When you approach a stationary emergency vehicle, tow truck, or any vehicle show... | – |
Tap a state for source citations and full Following-Distance & Headlight Rules detail.