If you do not count the increases in gasoline, renting a car will be fairly reasonable cost wise in 2008. The cost increases will be about 4 percent or less, owing mainly to the weakness in Detroit and the deals car manufacturers will be offering the large rental car companies.

Automobile renters with corporate accounts are not expected to see much of an increase as the bargaining power for the companies is still very strong. So if you are a small businessman or family looking to rent a car expect to see a modest increase in the price of a car rental when you travel.

The American Express Global Business Travel Forecast projects an increase in rental car rates next year of 4 percent or less.
Prices for airport car rentals “are a function of the number of people getting off of airplanes,” says consultant Neil Abrams, who advises companies on rental-car contract negotiations. “And as long as airline deplanements continue to rise . . . there will be some ability to raise” rates.
The National Business Travel Association forecasts a larger 2008 increase in rental car costs than does AmEx: 5 percent to 7 percent. But AmEx takes into account off-airport rentals, while NBTA does not.
Abrams and the NBTA expect the average rental rates paid by big corporations that can negotiate high-volume discounts with rental-car companies to rise only a bit, if at all.
To the extent that big corporations succeed in getting volume discounts, small companies and entrepreneurial business travelers will bear the brunt of rental-car companies’ expected revenue increases.
Gasoline prices also are likely to increase total spending on rental cars. via  IndyStar.com.

If you are traveling in the coming year expect to see costs go up. The combination of a strong economy and inflationary pressures will push the cost of travel up in every facet.

Hotels will see an increase over the rate of inflation but of all the major categories will go up the least in terms of year over year increases. As a matter of fact, the rise in hotel rates will be the lowest since 2003.

Business travelers continue to show an affinity for upscale, luxury hotels like Ritz-Carlton and Four Seasons. And a large number of road warriors continue to find their way to midpriced chains like Hampton Inn and Holiday Inn Express.
In response, proprietors of those two kinds of hotel properties can be expected to raise their prices more than any other hotel types in 2008, according to PKF Hospitality Research.
PKF predicts the average room rate in the U.S. will go up about 5.3 percent, to just over $109 a night. But rates in the luxury segment will rise 6.6 percent to an average of nearly $309 a night. Midmarket hotels lacking formal food and beverage operations are forecast to bump up their prices 6 percent to $92 a night.
The American Express Business Travel Forecast paints a similar picture for hotel price increases next year: up 4 percent to 6 percent in the midmarket segment; up 5 percent to 7 percent in the higher-priced segments of the market. via IndyStar.com.