Which direction is the economy headed? Check the compass on the dashboard of your recreational vehicle.

RV makers have foreshadowed the economy’s decline and illuminated its recovery in the last four domestic cycles, government and trade-group data show according to a Bloomberg report.

RV sales are watched by analysts because motor homes and travel trailers are discretionary purchases that are often not made during tough economic times.

Over a six-year period that ended in 2007, dealers averaged 355,000 deliveries. That number dropped to 237,000 in 2008.

Deliveries of RVs might rise in 2010, which would end a three-year decline, according to the report. July sales ran at the strongest annual rate since October, and by year’s end, shipments should show their first monthly gain since October 2007.

Shares of Forest City-based Winnebago Industries Inc. and Thor Industries Inc., two of the largest RV suppliers, have nearly doubled this year, though Winnebago has dropped 44 percent and Thor Industries 25 percent since the beginning of the recession.

Thor Industries announced it will add 200 workers to expand its travel-trailer output.

“The RV industry is always the first in and the first out, and there’s already been a noticeable beginning of it coming out of the current recession,” Dave Hoefer, an adviser to Earthbound Recreational Vehicles, told Bloomberg.