Few drivers escape this cultural habit. According to the little research available, the answer is Yes. However, it will take several more years to prove that aggressive driving habits causes crashes. We know that aggressive driving or RR causes stress and fear. Surveys have shown that all over the country and the world.
Common sense says yes, and so do the safety and insurance experts.
Because of two factors, one physical, the other psychological. Physically, the space between cars has reduced. The number of driving miles has increased faster than the miles of road available. Therefore there are more cars for the same amount of roadway, which means less space between cars. Congestion by itself need not be the cause of aggressive driving or road rage.