WSDOT

This is a tool to help you calculate permitted and legal weights. It will not print a valid axle spacing report. This page can be printed by following the instructions below (see Printing).

Axle Spacing Report Number – Allows an existing axle spacing report to be displayed (for axle spacing report numbers 10001 and greater only). Enter the desired axle spacing report number and click Look Up. This is helpful if a previous axle spacing report has axle spacing and tire values that close resemble the desired vehicle configuration.

Axle No. – Indicates a specific axle on the vehicle, where axle number 1 represents the front axle of the combination.

Axle spacing (ft). This can be entered in two different ways:

Feet with hundredths of a foot; 23.50

Feet – inches; 23-6 (Remember to use “–“ to separate feet and inches)

Tires per Axle – Number of tires on that entire axle.

Tire size – This can be entered as metric or inches. Inches can be specified in hundredths (for example, 12.75).

Steer Axle and Drop axle – This has three functions – You can click on it for help.

To designate steer axle steered by the driver – Click on STEER AXLE

To designate a self-steering drop axle - Click both STEER and DROP AXLE

To designate a non-steering drop axle – Click only DROP AXLE

Calculate – Once you have entered the above values, click “Calculate” at the top of the page to calculate permitted and legal weights.

Permitted Weight - These fields will automatically populate with the maximum weights allowed per axle. Keep in mind there are other factors to consider (spacing, number of tires, tire size) Example: Each axle of a tandem is allowed 22,000 lbs. maximum but the two axles together can not exceed 43,000 lbs. because that is the tandem weight limit.

Refer to Axle Restrictions and Remarks for additional weight restrictions on axles that have a “*” following their Permitted Weight value.

Total Permitted and Legal Weights

These fields will populate with the maximum weights allowed for the configuration using tire size, axle spacings and axle weights.

Remember: This will be for normal loads, to see if a permit for the desired weight can be issued for a specific vehicle combination. This tool cannot be used on loads such as the cranes, grandfathered vehicles and 8 tire axles. It also cannot be used for super loads. Super loads are limited not only by RCW weights but each bridge structure that the load affects on its route.

More Axles: Click to display additional axles if you require more than 10 axles.

Axle Restrictions and Remarks

This field will populate with the weight limits per axle groups listed.

Printing

To print the calculated weight information, click File/Page Setup and change your left and right print margins to .25 inches and click OK. Then click File/Print to send the page to your printer.