Should You Shift to P or N Gear When Waiting at a Red Light with an Automatic Transmission?

[KingMarie]

When waiting at a red light with an automatic transmission car, you should shift to N gear, and if the wait is longer, you can also engage the handbrake. It's fine to leave the car in N gear for a short time while waiting at a red light, but leaving it in N gear for an extended period can damage the transmission. An automatic transmission eliminates the need for the driver to manually shift gears, as the vehicle automatically selects the appropriate gear based on driving speed and traffic conditions. Typically, automatic transmission cars have six gear positions, arranged from top to bottom as follows: P (Park), R (Reverse), N (Neutral), D (Drive), S (Sport), and L (Low). Driving an automatic transmission car generally only requires using the P (Park), R (Reverse), N (Neutral), and D (Drive) gears to meet normal driving needs. However, in some special driving conditions, other functional gears may be necessary.

[HazelMarie]

I've been driving for over a decade and think putting the car in P gear at red lights is quite risky. Because P gear locks the transmission, if another car rear-ends you, the entire impact force is transmitted to the transmission, which can easily damage components and lead to expensive repairs. I've seen a friend have this kind of accident, costing over ten thousand to fix. So, for short stops like at traffic lights, it's better to use N gear or simply stay in D gear with the brake pressed. N gear keeps the transmission free, reducing burden, and also minimizes vibrations and noise, making the ride smoother. Of course, if the red light is particularly long or you're getting out of the car, then P gear is appropriate. Developing good daily driving habits can save a lot of trouble.

[JesseRose]

From a mechanical perspective, the P (Park) gear in automatic transmission vehicles has a locking mechanism designed to prevent rolling. However, using it during brief stops like waiting at a traffic light is actually unnecessary. If you do engage P gear and get rear-ended, the locking mechanism could suffer severe impact and potentially be completely damaged, leading to extremely high repair costs. Having studied cars for a long time, I find shifting to N (Neutral) gear more reasonable—it disconnects the power linkage, allowing the transmission to rest and reducing wear, without compromising safety. Personally, when waiting at a light, I shift to N gear and engage the handbrake, ensuring the car stays firmly in place and starts smoothly. This habit also saves a bit of fuel since it slightly reduces the engine load.

[McAlivia]

As a commuter, I prefer simpler operations at red lights. There's no need to shift to P; switching back and forth wastes time. I usually keep the car in D with the brake pressed, or shift to N for longer stops. D allows quick starts to avoid traffic delays, while N makes the car quieter and more comfortable, giving my foot a rest. Safety-wise, avoiding P prevents potential transmission damage in rear-end collisions. This habit doesn't affect fuel efficiency and protects the transmission lifespan.

[McHolden]

As a parent who drives my child to school, shifting to N (Neutral) gear at red lights is the safest and most comfortable option. If left in P (Park) gear and rear-ended, there's a higher risk of transmission damage, which is not only expensive to repair but could also affect the child. In N gear, the car remains stable with minimal vibration, keeping the child calm and quiet in the car. Every time at a red light, I shift to N gear and engage the handbrake, giving my feet a rest without worrying about fatigue leading to mistakes. In the long run, it's also better for the car, reducing stress on the transmission.