How to calculate turn radius of fifth wheel for new driveway

[howardwheeler]

I am putting in a new drive so that I can pull out my 37 foot Alpenlite rather than having to back it out (I know that’s extremely lazy but I have the opportunity because we must put in a completely new drive anyway and want to take advantage of it). Because of trees it would be nice to know what the sharpest turn can be knowing that the trailer will track inside the truck’s track. I will make the drive wider at the point of the turn to accommodate the trailer tracking inside the truck path, but since you pay for additional materials, it would be nice to figure out the minimum needed. I would take my trailer out in a parking lot and simply do some trial runs but I can’t move it before my friends will be here with the equipment to put in my main drive. I thought some here might have some formula for radius’s and how to determine how far inside the trailer will track from the truck. Thanks

[laknox]

BarneyS wrote:
Roundabouts are no problem if you go slow and watch.
Barney

=Especially= watch for the idiots that try and cut the corners and not stay in their lanes or simply can't figure out that something much longer than their car =is= going to cut corners. Personally, when I'm in that situation, I take up as much road as I can to prevent this kind of stuff.

Lyle

[BarneyS]

Roundabouts are no problem if you go slow and watch.
Barney

[RockyMt]

I would wonder if you could use the roundabouts now installed every where.

[valhalla360]

Puddles wrote:
Over the years, watching trucks running up on curbs... dropping off the edge of payment while trying to make a turn... I'm not sure I would trust any calculations provided by any highway engineering firm...

Driveways rarely get looked at by an engineer. The turning templates are typically used on road projects.

[2edgesword]

jkwilson wrote:

2edgesword wrote:
Wouldn't it be easier to back it in when you return from a trip so you can pull it out easily when you're ready to leave on the next trip?

My thinking is it's easier to back it in to the driveway from the street since you can pick your spot as far as timing the process and once you have the trailer partially in the driveway and the truck out of the street you can take your time getting the trailer line up how you want to park it.

I have a 32.5' travel trailer that I park in my drive. You can't back it straight in. When I get home from a trip I've got a 1/4 mile view up and down the road. I wait for a clear spot (no car in that 1/2 stretch) and get the trailer somewhat lined up so the end of the trailer is right at the entrance of the driveway. I back it into the driveway to the point where my truck is out of the street (takes about 20 ~ 30 seconds) and then, with no concerns about blocking traffic, I spend as much time as I need getting the trailer straighten up in the drive and leveled (3 ~ 5 minutes). Pulling out for the next trip takes all of 10 seconds.

I think you missed the OP's point. They are wanting a circular drive so they can pull in and pull out with no backing involved.

Since my drive is a quarter mile long, I have to have one as well.

I understood the point the OP was making. My thought was it would be more challenging trying to back out into the street with traffic and/or vehicles and/or other obstacles on the street versus backing into a driveway from the street.

Of course the ideal situation would be not having to do any backing into the driveway or out into the street. I just envision one VERY LARGE (wide) driveway would be required to do a 180° turn by a 37 foot long 5th wheel being pulled by a full size truck.

Here are some turn radius templates for tractor trailers of various lengths: Turn Radius Templates

Not sure how a 37' 5th wheel towed by a full size truck fits it but again, it looks like you would need a pretty wide driveway to complete a turn without having to back up.

[jkwilson]

2edgesword wrote:
Wouldn't it be easier to back it in when you return from a trip so you can pull it out easily when you're ready to leave on the next trip?

My thinking is it's easier to back it in to the driveway from the street since you can pick your spot as far as timing the process and once you have the trailer partially in the driveway and the truck out of the street you can take your time getting the trailer line up how you want to park it.

I have a 32.5' travel trailer that I park in my drive. You can't back it straight in. When I get home from a trip I've got a 1/4 mile view up and down the road. I wait for a clear spot (no car in that 1/2 stretch) and get the trailer somewhat lined up so the end of the trailer is right at the entrance of the driveway. I back it into the driveway to the point where my truck is out of the street (takes about 20 ~ 30 seconds) and then, with no concerns about blocking traffic, I spend as much time as I need getting the trailer straighten up in the drive and leveled (3 ~ 5 minutes). Pulling out for the next trip takes all of 10 seconds.

I think you missed the OP's point. They are wanting a circular drive so they can pull in and pull out with no backing involved.

Since my drive is a quarter mile long, I have to have one as well.

[laknox]

Hammerboy wrote:

Puddles wrote:
Over the years, watching trucks running up on curbs... dropping off the edge of payment while trying to make a turn... I'm not sure I would trust any calculations provided by any highway engineering firm...

I agree to an extent, just because something works on paper doesn't mean it will in real life. A lot of it is the skill of the driver in a tight turn, Some drivers can nail it every time and others can't

Dan

You want to talk skill? Saw a video of an Aussie(?) driver backing a set of triples into an enclosed warehouse through a standard rollup door. THAT's skill! :B

Lyle

[Hammerboy]

Puddles wrote:
Over the years, watching trucks running up on curbs... dropping off the edge of payment while trying to make a turn... I'm not sure I would trust any calculations provided by any highway engineering firm...

I agree to an extent, just because something works on paper doesn't mean it will in real life. A lot of it is the skill of the driver in a tight turn, Some drivers can nail it every time and others can't

Dan

[Puddles]

Over the years, watching trucks running up on curbs... dropping off the edge of payment while trying to make a turn... I'm not sure I would trust any calculations provided by any highway engineering firm...

[2edgesword]

Wouldn't it be easier to back it in when you return from a trip so you can pull it out easily when you're ready to leave on the next trip?

My thinking is it's easier to back it in to the driveway from the street since you can pick your spot as far as timing the process and once you have the trailer partially in the driveway and the truck out of the street you can take your time getting the trailer line up how you want to park it.

I have a 32.5' travel trailer that I park in my drive. You can't back it straight in. When I get home from a trip I've got a 1/4 mile view up and down the road. I wait for a clear spot (no car in that 1/2 stretch) and get the trailer somewhat lined up so the end of the trailer is right at the entrance of the driveway. I back it into the driveway to the point where my truck is out of the street (takes about 20 ~ 30 seconds) and then, with no concerns about blocking traffic, I spend as much time as I need getting the trailer straighten up in the drive and leveled (3 ~ 5 minutes). Pulling out for the next trip takes all of 10 seconds.

[valhalla360]

Is the proposed location for the driveway relatively flat with solid ground?

If yes, just drive the proposed driveway and mark it out as you go.

[Allworth]

A: parking lot big enough to turn a full circle.

B: a friend (or spouse) with a can of spray paint and a sense of humor.

Plan to go around the full circle three times.

circle 1 - paint a dab about every ten feet where the inside front wheels of the truck track.

circle 2 - paint a dab where the inside front wheel of the trailer tracks.

circle 3 - paint a dab where the outside tail of the trailer tracks.

Connect the dots if you wish.

Remember that results in the real world will probably be wider than under controlled conditions.

[jkwilson]

I tried for the same reason. It comes down to a lot of variables though. The truck wheels follow a different path than the trailer wheels, and you need to consider the path the back end of the trailer follows as well if there are obstacles.

I ended up just driving the most natural route i could find. I stopped when I was heading the other way and painted the boundaries of the inner and outer wheel paths left in the grass. Then I drove it a couple of more times trying to follow the first path to make sure it was a smooth route. Finally, I drove it again a couple of more times, turning a little early and a little late to see how that changed the route, and adjusted my borders.

[laknox]

Call the local Uni or Jr. Coll. and have some nerd there figure it out. Give them the measurements of your a) driveway, b) distance between pin and center of axles, c) width of truck & trailer, d) distance from center of axles to the =rear=. Bet it won't cost you more than a couple pizzas and a case of beer. :B

Lyle