For safety, yes. This prevents the car from lurching forward (or backward) if you start it thinking the transmission is in park/neutral, when it is actually in

For safety, yes. This prevents the car from lurching forward (or backward) if you start it thinking the transmission is in park/neutral, when it is actually in gear. Most modern cars have a lockout, preventing you from starting the engine unless the brake (or clutch) is pressed. However, some older cars do not have this feature.