Towing Speeds

[Larryzv7]

Why do you think States, like California, have a maximum speed of 55-mph when towing? Someone told me that the tires on most trailers, including semi-trucks, are not made for speeds over 55-mph; is this correct?

[Larryzv7]

Great discussion and thank you all for the various points of view. More than anything else what I am concerned about is road rage and impaired drivers; a study by the National Highway Safety Commission showed that States which have legalized marijuana are having more vehicle accidents than those that have not. The entire west coast of the U.S., California, Oregon, and Washington State, have all legalized marijuana for recreational use and I am concerned about what this may do to driving conditions which are already crazy on the interstate.

Nevada just opened up a drive thru for purchasing marijuana; you drive up, stay in your vehicle and buy your product at the window, and then drive away. I am not really talking about marijuana; rather I am talking about more people on the road impaired when we already had a bunch of people getting a DUI for alcohol. All of us need to be extra careful out there regardless of the posted speed. Although I do not tow at 55-mph in California because I think, as others have stated, that slower speeds can cause accidents just as much as higher speeds. 60 to 65-mph seems safe to me on the interstate. But I am glad to read about the different opinions on trailer tires and speeds which many of you have posted here.

Again, thanks for the discussion.:)

[rbpru]

I really do not care how fast the next person drives, if he is in a hurry to get to the accident scene so be it.

I know how fast I can drive and be comfortable, on the Interstate; it is 60 to 65 mph. On the US highways it is usually 55 to 60 mph or less.

On two lane roads try I try to pull over periodically and let the parade that formed behind me pass.

The plain truth is the fast, carless, and even drunk drivers rarely get caught, so it is unlikely that they will change any time soon.

[Community Alumni]

drsteve wrote:

I would not expect four drum brakes to stop a 15K 5er as quickly as four disc brakes will stop a 6K truck. Physics is not on the side of the 5er. So the truck is going to do some extra work.

This is why brake controllers exits with gain and boost settings. The controller activates the trailer's brakes in proportion to the TVs brakes. When setup correctly, the controller will apply proportional braking forces to the trailer relative to the force being applied by the TV. The trailer's braking should be equal or greater so that the trailer does not push the truck. If it does then there's a problem with the trailer's brakes or the setup of the controller.

I have my brakes setup so that when I press my brakes the trailer gives me a slight tug. As truck and trailer slows down, you can feel that the trailer's brakes are applying slightly more braking force than the truck. When you allow the truck to do the work you increase the risk of putting the truck into a skid or a slide with jackknifing being the end result. This is especially true when on low traction surfaces like wet or snow covered pavement or loose road surfaces.

[time2roll]

Passin Thru wrote:
I really don't care how fast you drive. Mind your business, I'll mind mine. Today, coming through Harrisburg Pa on I 81, one of the correct police was making 1 car pass him on the right then speeding up so 5 or six had to stay behind him. It's not a smart way to act these days when people will shoot you for being ugly.

Keeping to the right for others to pass is also an issue in CA that exacerbates the 55/70 split speed limit issues that most complain about. This makes for more weaving for those that want to travel 70+ mph.

[cooperrobt]

The 55mph restriction in CA is based on stopping distance.

[drsteve]

Passin Thru wrote:
I really don't care how fast you drive. Mind your business, I'll mind mine. Today, coming through Harrisburg Pa on I 81, one of the correct police was making 1 car pass him on the right then speeding up so 5 or six had to stay behind him. It's not a smart way to act these days when people will shoot you for being ugly.

In MI the cops will ticket you for that nonsense.

[Passin_Thru]

I really don't care how fast you drive. Mind your business, I'll mind mine. Today, coming through Harrisburg Pa on I 81, one of the correct police was making 1 car pass him on the right then speeding up so 5 or six had to stay behind him. It's not a smart way to act these days when people will shoot you for being ugly.

[time2roll]

Weight may or may not play into ability to stop depending on equipment. However travelling 10 to 15 mph slower will always stop faster and shorter in all conditions.

I use the cruise control to avoid creeping up in speed.

[1stgenfarmboy]

Every time I leave the house I say to myself, " OK lets go nice and easy " then I get on the road and people are passing me like I am build a garage around it, then I catch myself going 70+, I keep thinking as I get older I can get this under control, so far I have failed.


one day I will be able to go 55-60 on the entire trip.


this weekend we are headed out again, I think I have it this time as we are just going 30 miles from home. :B :B :B

[packpe89]

Nunyadamn wrote:
Do you think it could have to do with the construction of the road as well? I know the autobahn has something like 27" of concrete below the asphalt and they have a really strict maintenance program there. I think the CA roads (like most in the US) have 11". If we all drove our heavy trucks and trailers faster on the US roads it may play into the roads early destruction - potholes. Makes me think that is why the CA roads are so bad - we are all driving really fast on them and they can't/don't keep up with the maintenance. Plus there are so many more people driving vs more rural states/roads. If CA were to allow a higher speed, they would also have to repair the roads more and faster - $$$$$. I am sure there are a lot of factors that play into the reason. We could probably ask a legislator if we really wanted to know all of them.

There is not really a standard depth for interstates. Each roads pavement structure is designed for that road based on volumes and percent of trucks. I've worked on sections of interstate in NC and there is significantly more than 11" of road bed.

[Route_66_Travel]

As I mentioned back on Page 5, I drove a tanker in SoCal for 32 years. Gross weight was 80,000# and empty weight was 32,000#. Driving an empty trailer was much more dangerous than loaded because the trailer tires would lock up and skid, and the trailer would start to jackknife. Slippery roads compounded the problem always raised my pulse rate while in heavy traffic! When I retired in 2003 most newer tractors had anti-skid brakes, but tractor only, not the trailers. Don't know if that has been improved upon since '03.

The main thing to remember no matter what you are driving is to always give yourself enough room to stop and to keep alert. I also tell my wife to NEVER drive next to a truck and trailer, and if following a truck go where he goes if the truck makes a sudden lane change. It could save you from an accident.

In 32 years and a couple of million miles I never had an accident, but witnessed quite a few. Trucks in Arizona, as well as in many other States drive safely day after day at 75mph. California is its own oddity and will never change.

Think trucks can't stop fast in an emergency...check out this video and news story:

http://www.dailymail.co.uk/news/article-5076665/Heart-stopping-moment-child-avoids-hit-lorry.html

[drsteve]

proxim2020 wrote:

DutchmenSport wrote:

DanNJanice wrote:
... The faster you drive the more time to stop, the heavier you are the more time to stop.

True... and remember, time equals distance you know. It takes more distance to stop a 15,000 pound 5er, than it does to stop a 3,000 pound car. You may be able to stop the car at 60 mph in 200 feet; the 5er at 60 mph may take 1000 feet!

1000ft stopping distance would be valid if the trailer didn't have working brakes. The brakes equipped are designed to stop the GVWR of the TV and trailer respectively. Since the trailer will stop itself, there shouldn't be very much of a difference between stopping a fully loaded TV and one that's towing a heavy trailer. If the trailer is equipped with brakes then it should not push the TV. If it does then something is wrong.

Also, weight is only one factor that goes into braking distance. There's also the design of the braking system, tires, size of components, etc. It's perfectly possibly that a heavy combo can out brake a lightly loaded light vehicle. In this video, this truck stops faster than quite a few vehicles that I've owned that are far lighter. The kid may have not been so lucky if the vehicle was a car.

Video

I would not expect four drum brakes to stop a 15K 5er as quickly as four disc brakes will stop a 6K truck. Physics is not on the side of the 5er. So the truck is going to do some extra work.

[Turtle_n_Peeps]

Very well said proxim2020! On the money!

[Community Alumni]

To the OP
Most times speed limits set are for safety reason, but often times they are not. If the community or politicians feel it should be set to to a specific number then that what it's set to. For example, I live in a county where you can petition to have the speed limit lowered down to 20 mph in your neighborhood if more than half of the people agree to it. They won't do it on any major thoroughfares, but all other streets are fair game. Having a good reason for it isn't even required. Sometimes this is done to curb speeders, but often neighborhoods do this to discourage and decrease the amount of thru traffic going through their neighborhoods.

Some unscrupulous municipalities artificially lower their speed limits to make it easier to catch speeders and get the revenue from it. Back in the early 2000's our highway speed limit was lowered from 65 down to 55 here in Houston. This wasn't for safety reasons, but legislators felt that lowering the speed limit would reduce the ground level ozone levels. Turns out it didn't have a huge impact and the state made improvements elsewhere. The speed limit was raised by 5 mph a couple of years after being lowered.

Speed limits are a lot like manufacturer tow and load limits. Often only those who set them know why they are set at that point. It's best just to follow the limits presented to you on a sign or sticker.