Summer trips are likely to be shorter this year as U.S. consumers adjust their plans to rising gas prices, two Purdue University professors said Monday.

Many Americans won't be traveling this summer, but it will be a choice, Liping Cai, director of the Purdue University Tourism and Hospitality Research Center, said in a news release.

Our experience tells us they will go shorter distances.

Since 2002, after the Sept. 11, 2001, terrorist attacks, the distance people travel from their homes on vacations has gradually gained 2 hours, Cai explained.

But, I think surging gas prices this year have dampened that trend, Cai said.

Cai and Associate Professor Joseph Ismail recommend travelers switch from cars to trains for travel and cut back on eating out when on the road.

Businesses should also adjust, catering to regional customers, they said.

If customers change their behavior, there is an opportunity for businesses, Cai said.