California gasoline prices rose to $4 a gallon for the first time in a year and a half as more motorists hit the road amid easing pandemic restrictions in the most-populous U.S. state. The price in the most-expensive U.S. fuel market is up about 10 cents over the last month, according to AAA, amid a rally in crude oil and expanding fuel demand nationwide. Gasoline consumption across the country is on track for its third straight monthly increase, which which would be the longest streak since last summer, Energy Information Administration figures showed.

Although California is alone among the 50 states in reaching the $4 mark, the rise may bode ill for the rest of the nation. Demand already is at the highest since pandemic lockdowns began kicking in early last year and as more cities and states relax virus restrictions, the economic activity that underpins energy demand is expected to blossom.

The price shock comes just 12 months after the worst oil rout in history sent the price of West Texas Intermediate crude, or WTI, into negative territory. The knock-on effect of the current rally may be surging fuel prices across the country.

“Remember last year at this time crude was at zero,” said Jeffrey Spring, a spokesman for the AAA auto club of Southern California. “Now we have WTI over $60, which is at a 2019 level.”

Gasoline futures climbed 2.4% to $2.0679 a gallon at 11:39 a.m. on the New York Mercantile Exchange, pushing the year-to-date advance to 47%. The national retail average was at $2.89 on Wednesday, up 3 cents in the last month. GasBuddy analyst Patrick DeHaan said chances are high that the national average will reach $3 this summer.