In Grand Junction, bicycle sales are soaring . In Glenwood Springs, more people are buyng hybrids . In Vail and Eagle County, carpooling is gaining traction . In the Roaring Fork Valley, from Aspen to Rifle, mass transit use is on the rise . Gas has hit $4.00 a gallon in Colorado. It's actually quite a bit higher in many places, particularly for the "87" mid-range fuel. I paid $3.95 in Denver on Thursday. On Friday, I drove to Aspen. During the drive, a news announcer on the radio advised that due to a huge increase in the price of crude oil, motorists should fill up before going home from work,. He said gas stations would be charging more as early as Friday night. When I got off I-70 in Glenwood around 6:00 pm, I started checking the signs at gas stations. The price was $4.35 in Glenwood and $4.27 in Basalt. (I filled up in Basalt.) In Aspen, 40 minutes later, it was $4.65 a gallon. Returning home today, I paid $4.38 in Idaho Springs. Bottom line: It would have cost the same to fly on Frontier which has an introductory rate from Denver to Aspen of $79 each way , plus taxes, until June 11. I suspect $5.00 a gallon is around the corner and tourism will take another hit this summer as the total cost of vacations rises along with gas prices. I don't care what the economists and other policy wonks think -- a temporary suspension or cut in gas taxes would be very welcome relief right now.