Planning a Road Trip? check where gas prices are highest and lowest across the US right now
Summer road trip traffic is picking up across the US as drivers watch fuel costs closely in late July. The latest state-by-state averages from AAA on July 21 show a wide gap between the most expensive and least expensive places to fill up. That matters for travelers crossing multiple states, especially in the West, South, and Midwest, where prices can shift fast over a few hundred miles.
California remains the highest, while Mississippi stays among the lowest
AAA said on July 21 that California had the highest statewide average for regular gas at about $4.74 per gallon. Hawaii, Washington, Oregon, and Nevada also ranked near the top, according to AAA’s daily fuel tracker. At the other end, Mississippi posted one of the lowest averages in the country at about $3.01 per gallon, with Louisiana, Texas, Oklahoma, and Arkansas also near the bottom.
The spread between California at roughly $4.74 and Mississippi at roughly $3.01 was about $1.73 per gallon on July 21, based on AAA data. For a 15-gallon tank, that difference adds up to nearly $26 between the highest- and lowest-priced states. AAA’s averages reflect statewide pricing, so drivers in major metro areas such as Los Angeles or San Francisco may still see pump prices above the state average.
Western states are still the priciest, but Gulf Coast drivers are paying less
The clearest regional divide is in the West, where California, Hawaii, Washington, Oregon, and Nevada continue to post the highest statewide averages, according to AAA. In the South and Gulf Coast region, Mississippi, Louisiana, Texas, and Oklahoma remain among the cheapest states for regular gas. The company has not released a separate road-trip ranking by interstate corridor, so exact costs along routes like I-10 or I-40 can still vary by city and exit.
For travelers, that means a route through Arizona, New Mexico, or Texas may cost noticeably less than one centered on California or Washington. AAA’s statewide figures do not confirm which individual stations are cheapest, and GasBuddy station-level prices can change several times in a single day. In practical terms, a family driving from New Orleans to Dallas is likely to face lower average fuel costs than a family driving from Seattle to San Diego this week.
Refining, taxes, and fuel rules are driving the gap
AAA and the US Energy Information Administration have said state fuel taxes, regional supply constraints, and environmental fuel requirements all play a role in pump prices. California’s higher taxes and stricter fuel blend standards have long pushed prices above the national average, while Gulf Coast states benefit from proximity to refining hubs in Texas and Louisiana. The Energy Information Administration has also noted that crude oil prices and seasonal gasoline demand typically rise during summer travel months.
For customers, the biggest takeaway is that geography still matters as much as national averages. AAA’s national average on July 21 sat well below California’s statewide price but above several Southern states, underscoring how uneven fuel costs remain. Unless refinery outages or supply disruptions change regional inventories, current AAA data shows Western drivers are still paying the most, while much of the South continues to offer the cheapest road-trip fuel.
