thumb|Newspaper clipping about carless days
Carless days was a petrol demand reduction scheme active in New Zealand from July 1979 to May 1980. Introduced by the Third National Government of New Zealand, during the 1979 oil crisis, the scheme prohibited owners of private petrol-powered vehicles to drive on a self-designated day of the week. The enabling regulations were one of several attempts to help the New Zealand economy after the oil shocks of the late 1970s—other such policies included the Think Big strategy.
Background
New Zealand in the first half of 1978 sourced 39% of its oil from Iran. These price increases decreased demand; a 24.8% price increase in May before the introduction of the carless days scheme reduced petrol demand by 11%. As a result of the oil shock and the difficulty in obtaining oil elsewhere in a tight market, in March 1979, the country was receiving approximately 10-15% less oil than it normally would. According to Energy Minister Bill Birch, buying oil on the spot market to supplement supplies was not possible due to the New Zealand's unfavourable balance of payments. Nonetheless, by June 1979, the oil shortage had been reduced to 5%.
Prior to the introduction of carless days, the government had implemented other measures to reduce petrol demand. One measure was the reduction of the speed limit from 100 km/h to 80 km/h in December 1973 during the earlier 1973 oil crisis. The lower speed limit remained in place until July 1986. Another measure implemented in February 1979, was the ban on the sale of petrol on weekends to most motorists with exceptions for emergency situations and essential users. Several countries including Switzerland, the Netherlands and West Germany implemented similar carless Sundays during the 1973 oil crisis. The government also encouraged the use of alternative fuels like Compressed natural gas and Liquefied petroleum gas. Interest free loans were provided for the conversion of vehicles to run on gas and subsidies were provided for gas refueling infrastructure. By 1985, nearly 7% of the car fleet had been fitted to run on CNG. In March 1979, the government launched a publicity campaign urging the public to reduce petrol use by 10% warning that it would have to implement carless days if sustained cuts to consumption were not made.
According to Bill Birch, the minister of energy at the time, the government considered rationing, but chose carless days instead as it required less regulation and was easier to start and suspend quickly.
Scheme
Under the carless days regulations, the owners of most private petrol-powered motor vehicles under , with the exception of motorcycles, were required to refrain from using their car on one day of the week, that day being designated by the owner. Exemptions were issued for essential services and those with no alternatives to using their own vehicles. Each vehicle displayed a coloured sticker on its windscreen which noted the day on which it could not be used. Infringements were punishable by a fine of up to $400 (approx. $2500 in 2022 dollars).
Thursday was the most frequently chosen carless day. By the time the regulations were suspended, 43% of registered vehicles had exemptions. revoked in December 1980 and in 1981 replaced with petrol rationing legislation (the Petroleum Demand Restraint Act 1981) that can be invoked in the future.
There were 3,136 successful prosecutions against those who broke the carless days rules. It is estimated that approximately 0.2% of the people breaking the rules were caught and prosecuted.