Transistor as a switch in active or saturation region?
When looking at current loads, as safe rule is to use the use not more than the rms value (0,707) of the supply available to the load as your guide. Motors are electromagnetic devices like transformers. Reactance during on and off state to the coils of the motor, places "funny" variances on the suppy line being switched and behave like flyback transformers. Therefore snubber cct are required. Easier to switch with relay. Snub cct I easiest. A bit noisy though. Transistors switching motors is common in small toy or devices. Remember if no brake is required, dc motors tends to generate small currents while turned off and slowing down. So far the 1N4148 has been doing IT for me. Let's assume the 1 amp motor is used because of the torque required, look at stepper motors. Experiment safely.