Mobility scooter controllers permit smooth acceleration
https://wiki-cable.win/index.php/Are_You_Getting_Tired_Of_Folding_Mobility_Scooters_For_Sale%3F_10_Inspirational_Resources_To_Bring_Back_Your_Love
Mobility scooter controllers allow smooth velocity and braking; level of sensitivity settings can be tuned for novices or advanced riders.