Worries about traffic and the condition of the roads topped the holiday travel concerns cited by drivers in a recent AAA survey.

The organization is predicting a busy start to the summer travel season, suggesting that a record 38 million people in the United States will hit the road for Memorial Day weekend. Fifty-six percent of the 1,006 adults surveyed between April 28 and May 1 said they were planning a summer road trip.

Continuing low gas prices were contributing to these plans. AAA said the national average for a gallon of gas was $2.26 in mid-May, the lowest price since 2005 and 45 percent less than the same time in 2015. More than half of the survey respondents said low gas prices were the reason they decided to travel during the summer.

However, few drivers are anticipating a worry-free road trip. Eighty-one percent said they have concerns related to some aspect of their trip, with 69 percent citing road conditions or traffic.

Forty-eight percent said they are worried that there will be too much traffic or congestion during their drive. Forty-six percent expect there to be delays due to the repair or construction of roads.

Thirty-six percent said they expect to encounter unsafe road and bridge conditions, while 15 percent said they have other concerns related to roads or bridges. Although 69 percent indicated that they believe the roads will be in good or fair condition, only 19 percent expect them to be in very good or excellent repair. Eight percent said they think the roads on their route will be poor.

"Bad roads and traffic gridlock can make summer travel unpleasant and costly for all U.S. drivers," said Jill Ingrassia, managing director of government relations and traffic safety advocacy at AAA. "While low gas prices are getting people back behind the wheel this summer, bad roads can hit them hard in the pocket."

A previous study by AAA determined that damage caused by potholes—including flat tires, bent wheels, and damaged suspensions—cost U.S. drivers an estimated $3 billion a year over the course of the past five years. The organization says the typical repairs for this damage range from less than $100 for some tires to more than $1,000 for suspension repairs.

In addition to these costs, AAA says American drivers collectively spent 7 billion hours and wasted 3 billion gallons of fuel while stuck in traffic in 2015. It estimates that traffic congestion costs the average U.S. driver $960 a year.