Equivalent Single Axle Load ESAL Calculator
Highway traffic analysis & transportation engineering: Calculate cumulative 18-kip Equivalent Single Axle Loads (ESALs) over pavement design life factoring compound traffic growth and vehicle class truck factors.
Traffic Volume & Growth Parameters
Design Cumulative ESAL Results
Recommended Tools & Equipment
Tested hardware and components for high reliability
Frequently Asked Questions
Why do passenger cars contribute virtually zero ESALs?
A 4,000 lb passenger car has axle loads of 2,000 lbs (2 kips). By the fourth-power law: (2 / 18)⁴ = 0.00015 ESALs. It takes over 6,000 passenger cars to equal the pavement structural damage of a single standard 18-kip truck axle pass.
What is a typical Truck Factor (TF) for tractor-trailers?
A loaded 5-axle Class 9 tractor-semitrailer (18-wheeler at 80,000 lbs gross vehicle weight) typically exhibits a Truck Factor between 1.2 and 2.4 ESALs, depending on whether it carries bulk commodities or low-density freight.
Why is lane distribution DL important on 6-lane highways?
Traffic laws and slow climbing speeds confine heavy trucks primarily to the rightmost shoulder lane (Lane 1). Placing 80% to 90% of all corridor ESALs into a single lane means the outer lane requires substantially thicker structural depth than passing lanes.