Photo: Luke Miller, Pexels
Use high beams on dark open roads when no one is near, and switch to low beams when another vehicle approaches. Most US states require it within 500 feet of an oncoming vehicle, and within 200 to 350 feet of a vehicle you are following, depending on the state. This guide is for new drivers and permit test takers. It covers when headlights must be on, the dimming distances by state, the “wipers on, lights on” laws and how to handle glare.
Key facts
- Oncoming traffic: dim within 500 feet in the state handbooks covered here.
- Following a vehicle: dim within 300 feet in California, Pennsylvania, Alaska and Kentucky; 200 feet in New York and Alabama; 350 feet in Oregon.
- When lights must be on: typically from sunset (or 30 minutes after) to sunrise (or 30 minutes before), and whenever you can’t see a set distance ahead, often 1,000 feet.
- Wipers on, lights on: California and Pennsylvania require headlights whenever you use your wipers because of the weather.
- Don’t overdrive your headlights. Pennsylvania says low beams light only about 250 feet ahead, so on a dark road you should not drive faster than 45 mph.
When to use high beams
- Use them: on open country roads and dark city streets when no vehicle is close (California).
- Switch to low beams: when a vehicle comes toward you or you close in on one ahead, within your state’s distance.
- On lighted roads, use low beams (Idaho).
- In rain, snow, fog or smoke, use low beams. Pennsylvania says high beams actually reduce visibility in bad weather, and California says they reflect back and cause glare in fog.
- Where they are illegal, don’t use them (California).
High beam dimming distances by state
| State | Oncoming vehicle | Vehicle ahead (same direction) |
|---|---|---|
| California | 500 feet | 300 feet |
| Pennsylvania | 500 feet | 300 feet |
| Alaska | 500 feet | 300 feet |
| Kentucky | 500 feet | 300 feet |
| New York | 500 feet | 200 feet (even in another lane) |
| Alabama | 500 feet | 200 feet |
| Oregon | 500 feet | 350 feet |
| Idaho | Dim when approaching (no distance given in the manual) | Dim when following, and on lighted roads (no distance given) |
For other states, check your handbook. If you aren’t sure, dim as soon as you see another vehicle’s lights, as Pennsylvania advises for oncoming traffic.
When must headlights be on?
| State | Time of day | Low visibility rule | Other |
|---|---|---|---|
| California | 30 minutes after sunset to 30 minutes before sunrise | When too dark to see 1,000 feet ahead | Low beams on when wipers are needed for fog, rain or snow; on mountain roads and in tunnels; where signs say so |
| Pennsylvania | Sunset to sunrise | When you can’t see people or vehicles 1,000 feet ahead | Wipers in use because of weather; all posted work zones; daytime running lights alone aren’t enough |
| Alaska | Half an hour after sunset to half an hour before sunrise | Daytime visibility of 1,000 feet or less (fog, rain, snow, smoke or dust) | Don’t drive on parking lights only |
| Alabama | Half an hour after sunset to half an hour before sunrise | When you can’t see clearly for at least 500 feet | If in doubt, turn on low beams |
| Idaho | Sunset to sunrise | Visibility reduced to 500 feet or less | Low beams are best in fog, smoke, dust or rain |
Driving on parking lights alone is illegal in California and warned against in Alaska and Alabama.
Wipers on, lights on
- California: if you need your wipers because of fog, rain or snow, you must turn on low beams.
- Pennsylvania: since January 28, 2007, headlights must be on whenever wipers are in continuous or intermittent use because of weather. Tail lights must be lit too, so daytime running lights don’t count. The fine is $25, but with fees the penalty approaches $100.
Don’t overdrive your headlights
Overdriving means going so fast you can’t stop within the distance your lights show.
- Pennsylvania: low beams shine only about 250 feet ahead, and stopping from 55 mph on dry pavement takes more than 250 feet. On a dark road, don’t drive faster than 45 mph on low beams.
- Idaho: you can see about 350 feet with high beams and about 100 feet with low beams. Drive slowly enough to stop within the distance you can see.
- California: make sure you can stop within the distance lit by your headlights.
How to deal with headlight glare
Oncoming high beams
- Don’t look directly at the lights.
- Look toward the right edge of your lane and watch the other car from the corner of your eye (California). Idaho says to shift your eyes to the lower right side of your lane.
- If a driver forgets to dim, Pennsylvania says you may flash your high beams quickly a few times.
- Don’t retaliate by keeping your own high beams on. California and Pennsylvania both say it only makes it harder for both of you to see.
Glare from behind
Switch the inside mirror to its night setting (Pennsylvania).
Sun glare at dawn and dusk
California suggests keeping the windshield clean inside and out, wearing polarized sunglasses, keeping your visor clear and leaving extra space. Idaho warns never to wear sunglasses when light levels are low, and calls twilight and dawn the most dangerous times of day.
Night driving tips for new drivers
- Look harder for people. Pennsylvania says pedestrians are the hardest things to see at night, and California says motorcycles, pedestrians and cyclists are much harder to see.
- Leave more following distance and more time for passing (Idaho). Pennsylvania calls passing at night the most dangerous kind, because you can’t judge distance well from headlights alone.
- Let your eyes adjust: after leaving a brightly lit place, drive slowly until they do (California).
- One light coming toward you? Keep well right: it could be a motorcycle, a bicycle or a car with a broken headlight (California).
- Clean your headlights. Pennsylvania says dirty headlights may give only half the light they should.
- Watch for animals on rural roads. See deer and animal collisions.
- Don’t drive tired. See drowsy driving.
- Wrong-way check: California says that if road reflectors shine red in your headlights, you are going the wrong way.
Night driving and teen license rules
- Practice hours: most states require some supervised night hours. California, for example, requires 50 hours with 10 at night. See supervised driving hours by state.
- Curfews: most provisional licenses ban late-night driving at first. California bans driving between 11 p.m. and 5 a.m. in the first 12 months, with exceptions. Compare states in US graduated driver licensing compared.
- Road test: California scores failing to use headlights when darkness or weather requires them.
Permit test practice: headlights
These are unofficial practice questions, written for this guide.
- In most states, you must dim your high beams for an oncoming vehicle within: A) 100 feet B) 200 feet C) 500 feet D) 1,000 feet. Answer: C. 500 feet in every handbook checked (handbook: using your headlights).
- In California, you must dim your high beams when following a vehicle within: A) 100 feet B) 300 feet C) 500 feet D) 1,000 feet. Answer: B. 300 feet (California handbook: using your headlights).
- An oncoming driver doesn’t dim their high beams. You should: A) Keep your high beams on B) Look toward the right edge of your lane C) Stare at their lights to judge distance D) Stop in your lane. Answer: B. Don’t look into the lights or retaliate (handbook: darkness).
- Which lights should you use in fog? A) High beams B) Low beams C) Parking lights only D) Hazard lights only. Answer: B. High beams reflect back and cause glare (handbook: fog).
- In Pennsylvania and California, turning on your wipers for rain means you must also: A) Turn on hazard lights B) Turn on your headlights C) Slow to 30 mph D) Use high beams. Answer: B. Wipers on, lights on (handbook: headlight laws).
- “Overdriving your headlights” means: A) Using high beams in town B) Driving too fast to stop within the distance your lights show C) Leaving lights on after parking D) Driving without headlights. Answer: B. Pennsylvania suggests no more than 45 mph on low beams on a dark road (handbook: night driving).
More practice: US permit practice tests.
Common questions
When should you use high beams?
On dark roads with no vehicle close ahead or coming toward you. Switch to low beams within 500 feet of oncoming traffic and within your state’s following distance (200 to 350 feet).
How far ahead do low beams light the road?
About 250 feet, according to Pennsylvania; Idaho’s manual says you can see about 100 feet with low beams and 350 feet with high beams.
Is it illegal to drive with only daytime running lights at night?
Yes, in effect. Headlights must be on at night, and Pennsylvania says daytime running lights aren’t enough because tail lights must be lit too.
Can I flash my high beams at a driver who doesn’t dim?
Pennsylvania’s manual says you may flash them quickly a few times. Then look toward the right edge of the road rather than keeping your brights on.
Do I need headlights when it’s raining in the daytime?
In California and Pennsylvania, yes, whenever your wipers are on because of the weather. Many other states have similar rules.
Why is night driving more dangerous?
Pennsylvania lists limited vision, glare, and more tired or impaired drivers on the road. Distances, colors and side vision are all harder to judge.
Back to learning to drive in the USA. Related: driving in snow, fog and rain and rural roads and passing.
Sources
- California DMV, “California Driver’s Handbook: Section 5, An Introduction to Driving; Section 8, Safe Driving; Section 2, Getting an Instruction Permit and Driver’s License” (dmv.ca.gov)
- California DMV, “Driving Performance Evaluation (DPE) Scoring Criteria” (dmv.ca.gov)
- Pennsylvania Department of Transportation, “Pennsylvania Driver’s Manual” PUB 95, Chapter 3: Learning to Drive (pa.gov)
- Alaska Division of Motor Vehicles, “Alaska Driver Manual” (Rev. 10/2025), Use of Lighting Equipment (dmv.alaska.gov)
- Alabama Law Enforcement Agency, “Alabama Driver Manual” (November 2024) (alea.gov)
- Idaho Transportation Department, “Idaho Driver’s Manual” (July 2026), Night Driving (itd.idaho.gov)
- California DMV, “California Driver’s Handbook: Safe Driving” (dmv.ca.gov)
- Kentucky State Police, “Kentucky Driver Manual” (updated July 2026) (kentuckystatepolice.ky.gov)
- Kentucky State Police, “Driver Testing” (kentuckystatepolice.ky.gov)
- New York State DMV, “New York State Driver’s Manual” (dmv.ny.gov)
- Oregon DMV, “Oregon Driver Manual: Safe and Responsible Driving, Hazardous Conditions” (oregon.gov)