Carpooling reduces the costs involved with commuting by sharing travel expenses such as fuel, and tolls between the people travelling. Carpooling is a more environmentally friendly way to travel as ridesharing reduces carbon emissions, traffic on the roads, and the need for parking spaces. Authorities often encourage carpooling, especially during high pollution periods and after fuel costs rise. Carpooling where the driving is shared can also decrease driving stress as each driver gets a break from being at the wheel.