HS20-44 Truck Tire Spacing

[CivilStructural07]

Does anyone know the O.C. spacing between the 2 outer tires on either side of the rear axles?

 

[dougantholz]

Its about 18" center to center. The tires are about 8-10 inches wide and there is another 4-6 inches of gap created by the axle.

 

[crossframe]

The rear tires are spaced at 6'-0" o.c. per Figure 3.7.7A of the Standard Specs (17th Ed.). The tire contact area can be found in AASHTO 3.30, and comes out to around 10 inches in the direction of travel, and 20 inches wide.

I'm sure these same values are buried somewhere in the AASHTO LRFD specs, too.

 

[bridgebuster]

For design purposes the spacing is 6' as crossframe state; the overall width of the truck is taken as 10'.

The spacing of the outer wheels is not relevant for design; it's not a real truck.