Gasoline prices in Massachusetts and nationwide are the highest ever heading into Labor Day weekend, causing some drivers to rethink travel plans for the end-of-summer holiday.

A gallon of regular unleaded gas in Massachusetts averaged $3.73 a gallon at the beginning of the week, up 12 cents from a year ago and a record price for this time of the year, according to the Automobile Association of America. With Hurricane Issac forcing oil rigs and refineries along the Gulf coast to shut down, prices have continued to rise.