WASHINGTON – After a decade of steady increases, motorcyclist deaths nose-dived last year, possibly due to bikers watching their budgets in a sour economy.

The study, set for release today, indicates a 16 percent drop in U.S. motorcycle fatalities through the first nine months of 2009 compared to the same period in the previous year. It projects at least a 10 percent decline in fatalities over the entire year, or about 530 fewer deaths.

The 5,290 motorcyclist deaths in 2008 was the highest ever.

The study — authored by safety consultant James Hedlund, a former National Highway Traffic Safety Administration official — is drawn from preliminary fatality data from all 50 states, although data from some states was incomplete. The study was sponsored by the Governors Highway Safety Association, which represents state traffic safety agencies,

There is nothing in the data to indicate the cause of the sudden decline, but it is most likely due in part to a cutback in recreational driving, Hedlund said.