Rick Ricart is expecting nearly 40 Kia Telluride sport-utility vehicles to arrive at his family’s dealership near Columbus, Ohio, over the next three weeks. Most will be on his lot for just a few hours.

“They’re all sold,” Ricart said. “Customers have either signed the papers or have a deposit on them. The market is insane right now.”

In showrooms across the country, Americans are buying most makes and models almost as fast as they can be made or resold. The frenzy for new and used vehicles is being fed by two related forces: Automakers are struggling to increase production because of a shortage of computer chips caused in large part by the pandemic. And a strong economic recovery, low interest rates, high savings and government stimulus payments have boosted demand.

The combination has left dealers and individuals struggling to get their hands on vehicles. Used car prices are up about 45% over the past year, according to government data published this week. New car and truck prices are up about 5% over the past year.

Government stimulus may have helped some consumers, but it is hard to say how much. There are several large forces at play.

The chip shortage, for example, is affecting automakers all over the world. Industry officials blame limited production capacity for semiconductors and pandemic-related disruptions in supply and demand for the shortage.

To make the most of limited chip supplies, General Motors has temporarily done away with certain features in some models, like stop-start systems that automatically turn off engines when cars stop for, say, a traffic light. And the French carmaker Peugeot has replaced digital speedometers with analog ones in some cars.

Even though the unemployment rate is still higher than before the pandemic, many people have money to spend. Government payments have helped lots of people, but many Americans, kept from vacationing or eating out, saved money. Financing cars is also relatively cheap — at least for people with good credit. Some automakers like Toyota, which has been less affected by the chip shortage than others, are advertising zero-interest loans on some cars.