If you want to add animated vehicles to you 3d scene in 3dmax the best option for you is AntTrafficSimulator. Adding animated vehicles to your scene used to be a frustrating chore. Having to deal with rig setups, animation controllers, writting expressions, keyframe animations, terrain following, secondary motion.
With Ant Traffic Simulator, you select your vehicle and press one button to rig it. Select the path to follow and press a button to have your vehicles following it with proper wheel rotation and steering. Choose the terrain you want to be followed and with couple clicks your vehicles will follow it.
Feature list of AntTrafficSimulator
Automatic vehicle rigging for multiple vehicle styles and sizes
Works with Vray Proxy and Mental Ray Proxy objects
Works with instanced geometry to save memory
Automatic secondary motion for added realism
Path following with proper wheel rotation and steering
Automatic looping on the path for continuous animation
Vehicle speed setting in Miles per Hour
Traffic setup with random vehicle placement on chosen paths
Animated path switching to simulate lane changes
One click vehicle stops with easing in and out
Quick selection buttons for rigs and vehicle objects
Cars per hour calculator for realistic traffic simulation.