Although the Roxborough  Railroad failed to provide access to the rural sections of Roxborough  for suburban development, the construction of the Walnut Lane Bridge  over the Wissahickon in 1907 and 1908 did better connect Roxborough to  Germantown and open the way for development of the open land overlooking  the valley (Figure 38). Until the bridge opened at the dawn of the  automobile era in 1908, traveling between Germantown and Roxborough  required the steep descent into the gorge and the equally steep climb  out of it, an extremely difficult task in the era of horse-drawn  carriages and wagons. Constructed by engineers of the City of  Philadelphia, the concrete arch bridge, the longest single-span masonry  arch in the world when completed, was considered an engineering marvel.109

While the Walnut Lane Bridge  offered a convenient connection to Germantown, Roxborough’s boosters  still wanted a direct connection to burgeoning North Philadelphia and to  the downtown beyond that did not require negotiating the steep hill up  the Ridge from the Schuylkill or the deep Wissahickon gorge. The Henry  Avenue Bridge, which carries Henry Avenue over the Wissahickon and  Lincoln Drive, was contemplated as early as 1912 as part of a subway  extension plan, but was not implemented for nearly two decades. By the  time it was implemented, the automobile had supplanted all other forms  of transportation. After many years of planning and false starts, the  bridge was designed by prominent engineers Ralph Modjeski and Frank  Masters in collaboration with renowned architect Paul Cret in 1927,  constructed in the early 1930s, and completed in May 1932. At the same  time, Henry Avenue was extended from East Falls, across the Wissahickon,  and through Roxborough to Ridge Avenue in the Andorra section. The  wide, four-lane boulevard, which runs along the western boundary of the  Wissahickon section of Fairmount Park, was designed for automobiles, not  horses or trolleys, and opened the remainder of Roxborough for suburban  development. Although the mass transit facilities were built into the  bridge, no transit line was run along Henry Avenue and the bridge’s  transit facilities were never used. Even before the bridge was  completed, real estate agents were marketing suburban homes along Henry  Avenue. For example, in 1927 real estate agents Mason & Bruhns  advertised an “exceptional home ‘In the Open Suburbs of Philadelphia,’  613 Walnut Lane at Henry avenue, adjoining the Wissahickon Valley and  proposed golf course. New Henry Avenue Bridge will enhance value.”110