For Automobility 1.3.0, Momentum no longer needs a separate download. Its handling, cruise control and vehicle settings are included in the main Automobility JAR.
Upgrading? Back up your world and configuration, remove the old standalone Momentum JAR and keep your saved settings and key bindings. Choose the Automobility 1.3.0 file for your Minecraft version and update server and clients together.
This is an integration announcement, not a new standalone Momentum release. The earlier Momentum downloads remain for their matching older setups; follow their exact Automobility requirements. Thanks to milkucha for the original Momentum mod.