# Gate width calculation for Passenger car design vehicle

I am trying to figure out the minimum gate width required for parking a car inside the house which has a 15 feet road in front of it. Please refer to the image below:

Plot is 20 feet wide. I have assumed 6 inch wall and 2 feet X 2 feet columns. These are just rough figures. I am yet to do proper calculation to come up with technically correct figures. Vehicle under consideration is 17 feet X 6 feet as shown.

I have referred to AASHTO - Geometric design of Highways and Streets document to come up some calculation. Here is the turning path for a passenger class design vehicle:

Road is in pink for good visibility of dimensions. Plot is on the right side of the road where the curved path leads to. I mentioned the vehicle to be of dimensions 17 feet X 6 feet but according to the code, P class design vehicle has a size of 19 feet X 7 feet and I am using it directly. I have kept the gate columns right next to the road so as to get maximum area inside house boundary. Right now, they are 19.5 feet apart but ultimately they will be kept at 20 feet. To keep things on a safer side, I assumed the arcs to be circular and took the inner radius as 14 feet (instead of 14.4 feet) and outer as 26 feet (instead of 25.5 feet) and drawn this figure:

I am doing this for the first time and hence want it to be verified by you guys. By this design, I am getting a gate width of almost 16 feet. Are these calculations correct?

Is there any way I can reduce the gate width? Assuming that driver doesn't need to go into the house in one swing. He can make a partial turn, then reverse a bit and then align the vehicle properly to get it inside the gate. One thing that comes to mind is that vehicle under consideration is smaller than P class design vehicle (17'x6' as compared to 19'x7') but I don't know how to carry out the complete calculations for a given vehicle dimension. Also I am not sure whether reducing the dimensions of design vehicle will be a good idea.

EDIT:

1) This house is located in a very less crowded street (very few vehicles passing by) and one can always use full road width when trying to park the vehicle inside.

2) Moving the gate away from property line can be one way of reducing the gate width but property owner will be losing a good chunk of land which doesn't seem like a great idea. Also, the gate columns will have to be moved 11 feet inside to get a gate width of 13 feet - not a good idea at all.

• You can reduce the width of the gate opening by moving the gate away from the property line. Also I do not think it is right to assume you can be using the opposite side of the road all the time to make your turning movement unless its a one way road. Also, it appears you are using circles, where the path of the vehicle is actually some form of arc. – Forward Ed Jun 27 '16 at 21:28
• In your current sketch, the car ends up glued to the wall of the structure. However, the first image shows other columns also protruding from the wall, so the car will currently hit those. – Wasabi Jun 28 '16 at 11:59
• @Wasabi - Nice observation, sir. However I was just making a rough sketch and after fixing the gate size, I'll definitely make sure such mistakes are taken care of. I had an initial thought of using 10 feet wide gate which was horribly wrong. – Whiskeyjack Jun 28 '16 at 13:52
• Possible duplicate of How much clearance does a car need when turning a corner? – Wasabi Oct 8 '17 at 0:42
• If you were to reverse in you would need far less width clearance as the rear overhang of the vehicle describes a smaller arc than the front as the rear is closer to turning radius centre – Rhodie Jan 7 '19 at 1:00