# Vehicles \[FEA]

Vehicles define the axle configurations and wheel loads for design trucks, tandems, permit vehicles, and other vehicular load types used in live load analysis. The vehicle geometry (axle spacing, wheel spacing, and wheel loads) is defined in the vehicle's sub-objects.

## Data

**Factor:** A global scale factor applied to all wheel loads of this vehicle. Use 1.0 for the nominal vehicle weight. Factors other than 1.0 can be used to scale the vehicle for special loading scenarios (e.g., overweight permits or partial loading). Right-click any field in this spreadsheet for the action *Edit Wheel Loads...* which opens the vehicle editor to modify the axle configuration, wheel spacing, and individual wheel loads.

**Gross Vehicle Weight (readonly):** The total weight of the vehicle, computed as the sum of all wheel loads multiplied by the factor. This is a computed value and updates automatically when wheel loads or the factor change.

## Wheel Load Editor

When editing wheel loads via the *Edit Wheel Loads...* action, each row defines a wheel with the following columns:

* **X1:** The longitudinal position of the wheel. The front of the vehicle should be defined at X1 = 0, with rear axles at positive X1 values.
* **Y:** The transverse position of the wheel. For a standard vehicle, wheels are typically spaced 6 feet apart (e.g., Y = -3 and Y = 3).
* **X2:** Defines a range of variation for the axle position. If X2 is 0, the axle is at a fixed location. If X2 is nonzero, the axle position varies between X1 and X2, and the optimizer finds the critical placement within that range. For example, for the HL-93 design truck, the rear axle spacing varies between 14 ft and 30 ft.
* **Load:** The wheel load magnitude (force).