Key points
The maximum speed limit in Pennsylvania is 70.
Source: Handbook p. 39
“The maximum speed limit in Pennsylvania is 70.”
Pennsylvania Driver's Manual (PUB 95), Handbook p. 39Besides the posted limit, consider road conditions, visibility and the flow of traffic when choosing a safe speed.
Source: Handbook p. 38
“In addition to the posted speed limit, you must consider road conditions, visibility conditions and the flow of other traffic in choosing a safe speed to drive.”
Pennsylvania Driver's Manual (PUB 95), Handbook p. 38Use headlights when you cannot see pedestrians or vehicles 1,000 feet ahead.
Source: Handbook p. 40
“When they cannot see pedestrians or vehicles on the highway for a distance of 1,000 feet ahead of the vehicle they are operating.”
Pennsylvania Driver's Manual (PUB 95), Handbook p. 40Use low beams within 500 feet of an oncoming vehicle and within 300 feet of a vehicle you follow.
Source: Handbook p. 40
“Pennsylvania law requires you use low beams whenever you are within 500 feet of an oncoming vehicle and when you are following a vehicle within 300 feet.”
Pennsylvania Driver's Manual (PUB 95), Handbook p. 40To avoid overdriving your headlights on a dark road at night, do not drive faster than 45 mph.
Source: Handbook p. 40
“To avoid overdriving your headlights on a dark road at night, you should not drive faster than 45 mph.”
Pennsylvania Driver's Manual (PUB 95), Handbook p. 40You must turn on headlights whenever your wipers run because of weather.
Source: Handbook p. 43
“requires motorists to turn on their headlights anytime their vehicles wipers are in continuous or intermittent use due to weather conditions.”
Pennsylvania Driver's Manual (PUB 95), Handbook p. 43Roads are very slippery in the first 10 to 15 minutes of a rainstorm.
Source: Handbook p. 40
“Pavements can become very slippery in the first 10 to 15 minutes of a rain storm.”
Pennsylvania Driver's Manual (PUB 95), Handbook p. 40You can hydroplane at speeds as low as 35 mph in water only 1/10 of an inch deep.
Source: Handbook p. 41
“You can hydroplane at speeds as low as 35 mph, when water is only 1/10 of an inch deep.”
Pennsylvania Driver's Manual (PUB 95), Handbook p. 41On wet roads, slow by 5 to 10 mph and increase following distance to five or six seconds.
Source: Handbook p. 41
“Reduce your speed by 5 to 10 mph on wet roads and increase your following distance to five (5) or six (6) seconds.”
Pennsylvania Driver's Manual (PUB 95), Handbook p. 41In fog, do not use your high beams; the light bounces back and creates glare.
Source: Handbook p. 42
“Do not use your high beams. They direct their light up and into the fog, which bounces the light back into your eyes”
Pennsylvania Driver's Manual (PUB 95), Handbook p. 42
Numbers to know
| Number | What it means | Manual |
|---|---|---|
| 70 mph | maximum speed limit in Pennsylvania | Handbook p. 39 |
| 1,000 feet | if you cannot see this far, headlights on | Handbook p. 40 |
| 500 feet | dim for an oncoming vehicle | Handbook p. 40 |
| 300 feet | dim when following | Handbook p. 40 |
| 45 mph | top speed to avoid overdriving low beams | Handbook p. 40 |
| 10 to 15 minutes | most slippery part of a rainstorm | Handbook p. 40 |
| 35 mph | speed at which hydroplaning can start | Handbook p. 41 |
| 1/10 inch | water depth that can cause hydroplaning | Handbook p. 41 |
| 5 to 10 mph | slow down on wet roads | Handbook p. 41 |
| 5 or 6 seconds | following distance on wet roads | Handbook p. 41 |
3 questions from the Pennsylvania practice test
1. By how much does Pennsylvania's wet-road guidance advise reducing your speed?
- By 1 to 2 mph
- By 15 to 20 mph
- By 5 to 10 mph
- By exactly 25 mph
Show answer
By 5 to 10 mph. For wet pavement, the manual recommends reducing speed by 5 to 10 mph and increasing following distance. The question asks for the speed reduction, rather than the length of the following gap. A one- or two-mph change is less than the stated range, while the larger fixed reductions are not the figures given in this guidance. When the surface becomes wet, allow more room and make the recommended speed adjustment instead of simply continuing at the dry-road pace.
2. At what speed and water depth can a vehicle hydroplane, according to the Pennsylvania manual?
- Only above 70 mph in deep water
- As low as 35 mph in water only one tenth of an inch deep
- Only above 55 mph
- Only in standing water over an inch deep
Show answer
As low as 35 mph in water only one tenth of an inch deep. Pennsylvania's manual says you can hydroplane at speeds as low as 35 mph when water is only one tenth of an inch deep. Hydroplaning happens when the tires lose their grip and ride like skis on a film of water; the faster you drive, the less effective the tires are at wiping water from the road, and worn tires make it worse. Driving slower reduces the risk. If it happens, keep both hands on the wheel, slowly take your foot off the gas, do not slam on the brakes or turn suddenly, and steer only as much as needed to stay on the road.
3. When must a Pennsylvania driver turn on headlights because of weather-related wiper use?
- Only when the wipers have been running for 30 minutes
- Whenever the temperature drops below 32 degrees Fahrenheit
- Whenever the defroster has been running for five minutes
- Whenever the vehicle's wipers are in continuous or intermittent use
Show answer
Whenever the vehicle's wipers are in continuous or intermittent use. Pennsylvania's headlight and windshield-wiper rule links the two controls whenever weather requires continuous or intermittent wiper use. The driver must turn on headlights during that period, and daytime running lights alone are not enough because the tail lights must also be illuminated. The air temperature and the defroster do not start the requirement, and a waiting period of 30 minutes is not part of it. When rain or another weather condition starts the wipers, use the headlights at the same time and verify the rear lights are on.
Practice this topic
Lock it in with safe driving questions from the free Pennsylvania practice test. Every answer comes with a plain English explanation.
Source: the Pennsylvania Driver's Manual (PUB 95), Chapter 3: Learning to Drive. This lesson is a plain English summary, not the law itself; where it differs, the manual and the statute govern. Last checked 2026-09-27.