Complex sentence: A one-way spike strip will allow an automobile to travel over them in one direction; the spikes are hinged so that they collapse harmlessly when driven over in one direction, but remain upright when driven in another.
Split into simpler sentences: A one-way spike strip will allow an automobile to travel over them in one direction. The spikes are hinged so that they collapse harmlessly when driven over in one direction, but remain upright when driven in another.