on september 22, 1969, the reversible roadway between edsall road and sr 7 was converted to the first separated bus rapid transit (brt) route on an interstate highway during peak morning commute hours (0630–0930); this was extended north to shirlington the next day. the busway was extended to north of glebe road in september 1970, and then to the new center span bridge on april 5, 1971. the shirley highway express bus-on-freeway project was implemented from june 1971 to the end of 1974, demonstrating that brt on a highway was a feasible way to boost public transit ridership and on-time performance. however, compared to the lindenwold high speed line, a light rail service of comparable distance serving approximately the same number of people, prof. vukan r. vuchic found the shirley busway had fewer riders and revenue.