If you’re traveling this holiday weekend, you picked a good time to go. According to AAA, gas prices this Labor Day could be the cheapest in three years. Entering the day Thursday, the national average stood at $2.57 a gallon. That’s 25 cents cheaper than last year, and six cents cheaper than 2017. In Missouri, the statewide average is $2.29 a gallon. In the lake region, Camden County has the cheapest gas at $2.26 a gallon, followed by $2.32 in Miller County and $2.36 in Morgan County.