To ease congestion and increase convenience for drivers, 19 toll-lanes along the Dulles Toll Road will be converted from “exact change” to “E-ZPass only” over the next year, the Metropolitan Washington Airports Authority, which operates the road, announced Wednesday. During the conversion project, which begins Tuesday, Sept. 2, coin baskets will be removed and replaced by upgraded E-ZPass infrastructure.  Conversions are scheduled for unattended “exact change” lanes at the main toll plaza and exit ramps along the roadway.