The Mackinac Bridge has seen seven straight months of traffic numbers higher than in 2008, with 4.8% more traffic for the year and most recently a 0.6% traffic increase in October. The Mackinac Bridge Authority expects to end 2009 more than 4% higher than last year.

This will mark the first major traffic increase since 1998, said Bob Sweeney, Mackinac Bridge Authority executive secretary.

The 3,695,757 cars that crossed last year represented an 8.85% decrease in traffic from 2007, a trend that the bridge has seen over the last several years.

"It has been a great year for us, much better than expected," Mr. Sweeney said. Based on yearly economic and travel forecasts tracked by the bridge authority, a 6% drop in traffic was expected for 2009.

"We have been very pleasantly surprised with the increase we have seen," Mr. Sweeney said. "It's good news for us because we have a lot of major preservation work on the bridge coming up."

The fares collected from motorists crossing the bridge pay for the majority of such maintenance, he said. The bridge is wholly funded by tolls.

Fare revenue was down 1.4% in October , but is up 3.7% for the year, compared to 2008. As of the end of October, 3,400,691 vehicles have crossed the bridge this year, compared to 3,244,548 at this time in 2008.

In October, 342,057 vehicles crossed the bridge, just a hair more than the 340,071 that crossed in October 2008. Even in August, a month which should have seen less traffic this year owing to Labor Day falling in September, the bridge authority reported a 0.7% increase in traffic. September, which had the busy holiday weekend this year, saw a dramatic 18% increase in traffic, or 65,694 more cars than in 2008.

Passenger vehicle traffic, the bridge authority reported, is up 9% for the year, although commercial traffic has been down.

The biggest factor influencing this change from the bridge's forecasted numbers, Mr. Sweeney speculates, is the popularity of affordable in-state travel during the recession.

"Even though the economy in the state is down, people still have some time on their hands," he said. "They are looking into taking more economical vacations."

Lower gas prices this summer, combined with a very successful Pure Michigan advertising campaign are two other variables Mr. Sweeney said likely resulted in greater numbers of people crossing the bridge.

"The Pure Michigan campaign, I think, was a huge benefit to Michigan, northern Michigan, and the Eastern Upper Peninsula, as well," he said.

Mr. Sweeney said it is still too soon to tell what traffic in 2010 may look like, but said the bridge authority is currently forecasting a drop in traffic of 3%. This prediction will likely be adjusted in February, he said, after a number of economic and travel forecasts that the bridge authority watches each year are released.

The first of these forecasts will be the Michigan and U.S. economic forecasts by the University of Michigan's Research Seminar in Quantitative Economics. The release of this data, the 57th forecast the group has completed annually, is scheduled for November 20.

"They appear to be pretty accurate as to how the economy is going to fare for the year," Mr. Sweeney said. "We really watch those numbers very carefully."

The bridge also looks at tourism forecasts from the University of Michigan, the Michigan Department of Transportation's yearly travel trend forecast, and economic outlooks from the State of Michigan.

"We watch all of those," Mr. Sweeney said, "and our forecast comes out in February."

Turning this economic data into traffic forecasts is important in drafting the bridge's yearly business plans, he said.