Controlled Stop using Regen

Hi I read one of the posts where the user was trying to do a controlled deceleration after disconnecting SW2 in an emergency. One of your recommendations was to use a SPDT switch / relay at SW2 and connect the power leads to ground via a resistor. Would you not also need a resistor to stop an incredibly high instantaneous current on switching? Also with regards to the controlled electrical braking how would you size the resistor against deceleration?