Come May 1, the steadily increasing global price of oil may finally hit home for District residents who cab it to and from home, work and play. Taxi fares are set to increase by up to $1 a trip to offset rising gas prices, reports the Common Denominator. The increases will be implemented for a 120-day trial period, after which the D.C. Taxicab Commission will decide whether to make them permanent. Global oil prices have…