As an amateur race car driver, I’ve got a few things to add here.
There’s one very important tip I’ve never seen driver’s ed courses mention concerning rain driving: the available traction on wet pavement varies wildly depending on the surface. Rougher surfaces tend to offer more grip, some feel nearly as good as driving in the dry. Smoother surfaces tend to offer less, some (the worst blacktop parking lots) feeling as bad as driving on ice. Any paint (such as painted-on brick strips on some intersections) is going to be very slick, as is most concrete (as its generally smooth, though rougher concrete like is found on runways will have lots of grip). Between different types of wet asphalt the difference in grip of my race car (on street tires) can range from around 1.0 gees of maximum lateral acceleration to as low as 0.65.
Metal drawbridges are also extremely slick in the wet, to the point where a strong wind can blow a car into other lanes.
So unless your familiar with the surface you’re driving on, do not take anything for granted in the wet. On poor surfaces even a little bit of water can massively increase stopping distances. Unfortunately you can’t count on newer construction being better here, as the slickest interstate I’ve encountered was relatively new (if you can read a sign from its reflection off the wet surface, the road probably sucks).
I regard tips on how to drive (at night? during the rain? at what speed?) as being largely dependent on environment and visibility. You always need to be prepared to react to something as soon as you can see it. Rain, night time and curvy roads keep you from seeing things as quickly, and mean you need to be more conservative. Every time you drive faster than you can react to unseen dangers you’re rolling the dice. Always drive within your visibility. Sounds like common sense, but it doesn’t seem to be commonly followed.
Aside from working headlights, tires are the #1 accident-avoidance device on the car. Almost all cars on the road have brakes powerful enough to lock the tires up, meaning stopping distances are a function of available grip. They may look like simple blocks of inflated rubber, but tires are extremely complex and not at all created equal. The best tire for a vehicle is going to vary with wheel size, ambient temperatures and budget, and you definitely don’t always get what you pay for here.
All other things equal, more tread depth = more hydroplaning resistance. Bald tires can grip just fine in the wet provided there is no standing water, but this is generally not recommended for obvious reasons.
Some people say tire inflation pressures are critical. You definitely don’t want them more than 5 or so psi from ideal, but I’ve done a lot of testing here and not generally found pressures to make a measurable difference in overall grip when they’re kept within reason. Lower pressures feel “sloppier” but still grip, while high pressures feel “crisper” and probably save you some gas. A severely under-inflated tire can overheat and de-laminate just driving in a straight line, and no you won’t always notice this until the tread is already coming off. Tire pressure monitors are really great safety devices and I wish I had them on my race car.
Here’s an anecdote where tires saved the day: I was driving on the interstate and came upon a block of traffic. In front of me was a Toyota, and I slowed to match its speed. Less than a minute later the Toyota veers off the road and his right front tire hits a concrete construction barrier. The tire climbs up this barrier and flips the car onto its roof, landing in my lane. I was blocked in by traffic and had no other choice than to slam on my brakes and hope. The impact with the barrier slowed the car very quickly, to the point where I came within a few feet of hitting it. Once I matched its speed it skidded away from me as roofs obviously don’t slow cars down very well.
I was in a sports car equipped with aerodynamic downforce and road-legal racing tires. Had I of been been on economy tires I certainly would have hit the car with significant force. Had I of been in an SUV I likely would have run it over. As it was the driver crawled out of the car shaken and bleeding, but largely alright. He didn’t remember what caused the incident. As it was in the afternoon, I suspect he was distracted, dropped a tire off the road, and the pavement height change pulled on the steering and sucked the car into the barrier.
In hindsight I shouldn’t have been following so closely, though I was maintaining more distance than others in the block. I admit it never went through my mind that the car in front of me might veer off into a concrete wall and be deflected back into my lane.
So thats what I’ve learned: tires are very important, and rain needs respect to be handled safely.
As an amateur race car driver, I’ve got a few things to add here.
There’s one very important tip I’ve never seen driver’s ed courses mention concerning rain driving: the available traction on wet pavement varies wildly depending on the surface. Rougher surfaces tend to offer more grip, some feel nearly as good as driving in the dry. Smoother surfaces tend to offer less, some (the worst blacktop parking lots) feeling as bad as driving on ice. Any paint (such as painted-on brick strips on some intersections) is going to be very slick, as is most concrete (as its generally smooth, though rougher concrete like is found on runways will have lots of grip). Between different types of wet asphalt the difference in grip of my race car (on street tires) can range from around 1.0 gees of maximum lateral acceleration to as low as 0.65.
Metal drawbridges are also extremely slick in the wet, to the point where a strong wind can blow a car into other lanes.
So unless your familiar with the surface you’re driving on, do not take anything for granted in the wet. On poor surfaces even a little bit of water can massively increase stopping distances. Unfortunately you can’t count on newer construction being better here, as the slickest interstate I’ve encountered was relatively new (if you can read a sign from its reflection off the wet surface, the road probably sucks).
I regard tips on how to drive (at night? during the rain? at what speed?) as being largely dependent on environment and visibility. You always need to be prepared to react to something as soon as you can see it. Rain, night time and curvy roads keep you from seeing things as quickly, and mean you need to be more conservative. Every time you drive faster than you can react to unseen dangers you’re rolling the dice. Always drive within your visibility. Sounds like common sense, but it doesn’t seem to be commonly followed.
Aside from working headlights, tires are the #1 accident-avoidance device on the car. Almost all cars on the road have brakes powerful enough to lock the tires up, meaning stopping distances are a function of available grip. They may look like simple blocks of inflated rubber, but tires are extremely complex and not at all created equal. The best tire for a vehicle is going to vary with wheel size, ambient temperatures and budget, and you definitely don’t always get what you pay for here.
All other things equal, more tread depth = more hydroplaning resistance. Bald tires can grip just fine in the wet provided there is no standing water, but this is generally not recommended for obvious reasons.
Some people say tire inflation pressures are critical. You definitely don’t want them more than 5 or so psi from ideal, but I’ve done a lot of testing here and not generally found pressures to make a measurable difference in overall grip when they’re kept within reason. Lower pressures feel “sloppier” but still grip, while high pressures feel “crisper” and probably save you some gas. A severely under-inflated tire can overheat and de-laminate just driving in a straight line, and no you won’t always notice this until the tread is already coming off. Tire pressure monitors are really great safety devices and I wish I had them on my race car.
Here’s an anecdote where tires saved the day: I was driving on the interstate and came upon a block of traffic. In front of me was a Toyota, and I slowed to match its speed. Less than a minute later the Toyota veers off the road and his right front tire hits a concrete construction barrier. The tire climbs up this barrier and flips the car onto its roof, landing in my lane. I was blocked in by traffic and had no other choice than to slam on my brakes and hope. The impact with the barrier slowed the car very quickly, to the point where I came within a few feet of hitting it. Once I matched its speed it skidded away from me as roofs obviously don’t slow cars down very well.
I was in a sports car equipped with aerodynamic downforce and road-legal racing tires. Had I of been been on economy tires I certainly would have hit the car with significant force. Had I of been in an SUV I likely would have run it over. As it was the driver crawled out of the car shaken and bleeding, but largely alright. He didn’t remember what caused the incident. As it was in the afternoon, I suspect he was distracted, dropped a tire off the road, and the pavement height change pulled on the steering and sucked the car into the barrier.
In hindsight I shouldn’t have been following so closely, though I was maintaining more distance than others in the block. I admit it never went through my mind that the car in front of me might veer off into a concrete wall and be deflected back into my lane.
So thats what I’ve learned: tires are very important, and rain needs respect to be handled safely.