I’d say use cruise control in reasonably wet weather, not colder weather where there is potential for the road freezing.And use common sense and go 10 to 15 mph etc slower on highway.
A lot of that depends on where you live. Reasonably wet weather is a lot different in Florida than in Southern California.
On I95 drainage is very good, generally you will have visibility problems before traction problems.
1 Like
I think a lot of people think they have hydroplaned when they have not. If it has not rained in a long time, there is a lot of oil in the cracks and crevices of the road surface and that all floats on the water when it starts to rain. Also there are depressed groves in many areas where heavily loaded trucks are leaving to;; booths that are the width of tractor trailers. If you are in a car your tires can’t run in both grooves at once and it can make the handling squirrely when wet.
When I was running two 45’ empties down the Thruway, I had 26 wheels and the footprint of each tire was much large than a cars. I doubt if the pounds of pressure per square inch was as muck as a cars. I also don’t think the pressure within the tire has anything to do with it. In 60 some years of driving, cars trucks and buses I have never hydroplaned. I have slid for many reasons. Black ice, the popular name for what for many years was called glare ice is difficult to deal with. One second 65mph is too slow, the next second 10 mph is too fast.
1 Like
“The conditions that influence hydroplaning include speed, tire design, tread depth, water depth on the road, load on the tires, and inflation pressure …
Hydroplaning speed = 10.35 x 
inflation pressure”
https://one.nhtsa.gov/cars/rules/rulings/TPMS_FMVSS_No138/part5.6.html
Read the statement contained in the longer version.
“water depth exceeds the capability of the tread design to remove water”
Tread depth has a substantial impact on the probability of hydroplaning. If you make a simplifying assumption that the w Tread depth has a substantial impact on the probability of hydroplaning. If you make a simplifying assumption that the water depth exceeds the capability of the tread design to remove water (which most likely would occur with very worn tires), then an approximation of the speed at which hydroplaning can occur can be estimated by the following formula:
Hydroplaning speed� = 10.35 x square root sign inflation pressure [25]
Under this assumption of water depth exceeding the capability of the tread design to remove water:
At 30 psi, hydroplaning could occur at 56.7 mph
At 25 psi, hydroplaning could occur at 51.8 mph
At 20 psi, hydroplaning could occur at 46.3 mph.
This is presented to show the relative effect of inflation pressure on the possibility of hydroplaning. exceeds the capability of the tread design to remove water (which most likely would occur with very worn tires), then an approximation of the speed at which hydroplaning can occur can be estimated by the following formula:
Hydroplaning speed� = 10.35 x square root sign inflation pressure [25]
Under this assumption of water depth exceeding the capability of the tread design to remove water:
At 30 psi, hydroplaning could occur at 56.7 mph
At 25 psi, hydroplaning could occur at 51.8 mph
At 20 psi, hydroplaning could occur at 46.3 mph.
This is presented to show the relative effect of inflation pressure on the possibility of hydroplaning.
1 Like
I’d take that a step further.
When it hasn’t rained in a while, the first rain will make the roads very slick due to oil accumulation. So in a place like Southern California where it rarely rains, the roads will be very slick when they do get wet.
If you’re in Florida during monsoon season, when it rains almost every day, this is less of a concern, although it tends to rain a lot harder here when it does rain, so you can find yourself driving through standing water during a torrential downpour even when the roads are relatively clean.
My motorcycle safety instructor told us that, when it hasn’t rained in a while, and he encounters rain on his motorcycle, he stops for a cup of coffee. This gives the rain a chance to either stop or wash away the oil that has accumulated before he gets back on the road.
1 Like
Yep, we had safety films about that way, way back when I was in elementary school.
A simple mathematical model… A wise man once said, “All models are wrong, but some are useful”
I don’t think the model is accurate to one decimal place. Not sure it would be accurate even to 2 mph across the myriad of tire models and tread designs.
I’ve owned brand new tires that would hydroplane on damp pavement and others that could be driven through a 2 inch puddle at 70 mph … an exaggeration, yes, but not by much!
"The conditions that influence hydroplaning include speed, tire design, tread depth, water depth on the road, load on the tires, and inflation pressure."
load on the tires
That’s a biggie and can’t be overlooked. Problem is, how many folks actually know what the load on their tires actually is, and if they did know, could they factor the information in correctly.
Sorry to bore the regular contributors here with this anecdote that I’ve published a few times before, but here goes again…
Several (actually many) decades ago when I was on a Rocky Mountain high alpine ski trip on a highway above Denver somewhere in my nearly new (purchased new) 1971 Clementine Orange Volkswagen Super Beetle I made a strange discovery…
As often happens in Colorado, it had snowed and then stopped, the sun came out and in short time in the dry air, almost completely melted the snow cover and evaporated the precipitation, except a strip of slush along the center-line of the highway. The roads were otherwise dry.
What I discovered was that I could wander over to the slush with the Super Beetle, and at cruise speed, with the right side tires tire remaining on totally dry road, and the left side tires in the slush, watch the speedometer drop to ZERO mph and stay there until I steered out of the slush. Then with a lurch and the sound of an airplane touching down, the speedo shot to highway speed, like 55mph. I demonstrated this to my friend, the right seat passenger, and did it several times while I pondered what was happening.
Beetles had a mechanical “housed” cable linking the speedometer directly to the left front wheel. The cable went through a hollow, right through the spindle, through the center of the wheel bearings, and anchored in a square drive hole in the hub grease cap where it was secured with a circlip.
I was amazed to think that the Bug was hydroplaning on the slush to the point of stopping the front tire from turning, or turning extremely slowly.
As a driver of Volkswagen Type 1 vehicles for decades and hundreds of thousands of miles, in all kinds of weather and terrain conditions (including racing off-road buggies), I understand that the light front tire loading of these cars demanded one’s understanding and attention in inclement weather. Not doing so could cause a driver to feel instantly homesick or worse, much worse!
CSA
I remember replacing that cable on my 59 bug. Interesting design but easy to replace and you could even re-use the cotter key. I think it was a couple bucks.
I don’t see how hydroplaning can occur without some standing water.
I can imagine some rubber compounds having a poor COF when wet.
Especially when not broken in.
The “damp pavement” was an exaggeration! As I said right underneath the comment…
If you were driving a Mustang, or any other pony car I can understand why. Light weight, wide tires and a stiff suspension are a recipe for disaster in bad weather. I have never wanted wide tires, everything you gain in dry road traction is given back and then some when the road gets wet and snowy. I would much rather have a taller, narrower tire because I expect my car to be able to handle weather year round in Buffalo. The first cars we see up on top of the guardrail during the first snow are driving Mustangs and Camaros, only because the people with Corvettes usually put them away for the winter.
3 Likes
So racing slicks reduce traction? I’ve told this before and I just don’t buy the idea of wide tires having less traction. In school I lived below a pretty steep hill in South Dakota. My 59 Pontiac came with those wide ovals in the back. In the winter I went up that hill with no problem with my nearly bald wide ovals. Over Christmas vacation, I put normal size snow tires on and guess what? I couldn’t make it up the same hill again until Spring. So for me the wider the better. More rubber on the road. More traction. The idea of a narrow tire biting down to the pavement on snow is disproven by looking at the tracks in the snow. Snow is just compressed under the tires, not dislocated. IMHO and experience anyway and of I course I may be wrong.
1 Like
With normal 10 inch wide road tires, my Corvette was almost undriveable in snow. The tires were not meant to be snow tires. My 07 Mustang had 10 inch wide all season tires and it was OK. No real drama but you had to pay attention.
My current Mustang has 11 inch tires and the car has never seen snow, nor will it.
1 Like
YES! Endless Summer! That’s what I’m talking about! If man was intended to screw around with snow and ice he wouldn’t be born naked!
You go, Mustangman! 
P.S… When are we getting together for coffee? My Clearwater High School Friend, who owned a 66 fastback Mustang hypo 289 in High School, tells me there’s a great car museum with Mustangs in Sarasota, right in my backyard.
CSA
1 Like
Wider tires provide more traction most of the time, but they’d also be more prone to hydroplaning, I’d think. If you wanted to skip a rock on a pond, you’d want a nice wide rock with lots of surface area. Not a narrow one. More contact area on the tire also means more surface area, which will be more prone to hydroplaning.
I have 63 years of driving experience and more than 3 million miles of driving in the snow country of Western NY, driving cars tractor trailers and buses. Much of my experience was driving to or through Watertown Ny through Malone to Montreal. I was a freight hauler for many different class 1 common carriers. We did not get to chose where or when we went, and refusing a call was a firing offense. If you parked the rig because of snow, you had better cone back with the badge number of the cop who told you the road was closed.
Frankly, I am not interested in the theories of amateur drivers. Every trucking company has some drivers that can be counted on to get through in bad snow conditions. I was one of those drivers. Once, when driving for Transcon lines I left Buffalo behind a senior driver going to Indianapolis. I not only beat him to Indy but took my 8 hours off there came back to Buffalo took 9 off at home was caled out again and made another round trio with 8 off and beat him back to Buffalo two trips to one because he was so afraid of the blowing snow in Erie pa thet he went to bed there down and back.
The Edmunds article says “When the rain starts to fall and pavement is wet, your likelihood of a crash is higher than during wintry conditions like snow, sleet and ice … NHTSA researchers found that 46 percent of weather-related crashes happened during rainfall, but just 17 percent while it was snowing or sleeting.” But that conclusion doesn’t follow from the data presented; there are 3 times as many crashes in rain vs. snow and ice, but rain is also a lot more common in most of the country than snow. If rain occurs more than 3 times as often as snowy or icy conditions, then the latter is actually more dangerous.
Racing slicks have more traction than regular tires in dry conditions, because more rubber is in contact with the road, but in wet conditions, they have very little traction.
1 Like