Lane. However, as the primary roads through the park such as Jerome, Grand, and Mosholu Avenues were constantly maintained and upgraded, secondary roads fell into a state of neglect. One such road was Rockwood Drive, which was closed in 1936 and became a bridle path. Highway construction in the mid-1930s further altered the park. The first of these proposals was the Grand Concourse Extension, later the Mosholu Parkway Extension, which was already being paved in 1934, when Robert Moses became Parks Commissioner. Moses immediately started planning for the Henry Hudson Parkway, which was originally envisioned as an extension of Riverside Drive. As proposed, the parkway would have only skirted the park's northwest corner in order to connect with the Saw Mill River Parkway in Westchester. However, due to that plan's high cost, the route was amended and the Henry Hudson Parkway became an extension of the West Side Elevated Highway, cutting straight through the park to intersect with the Saw Mill River Parkway. Unlike the Concourse extension, the Henry Hudson Parkway was minimally opposed by the community, as it was widely seen as an improvement. Work on the parkway began in 1935. Simultaneously, work progressed on the Mosholu Parkway Extension, and Mosholu Avenue within the park was being modified so that it would be bisected by Henry Hudson Parkway. A bridge was constructed over the railroad in 1940, and a road linking the avenue and the new Mosholu Parkway was opened the next year. Mosholu Parkway was then extended to the Henry Hudson Parkway via a partial cloverleaf interchange built near the park's sole freshwater marsh. When biology teachers who used the marsh for their classes raised concerns about construction, an assistant to Moses said that the marsh would get a landscaping so that it looked like a series of lagoons surrounded by shrubbery. World War II halted all highway construction. By the time the war ended, Moses had become a Construction Coordinator for the city, and in 1947, proposed the Major Deegan Expressway through the park. Since community leaders had some objections to the proposal, Moses held a public hearing to discuss it. Opponents of the plan stated that the expressway would carry heavy truck traffic, as opposed to the existing parkways, where trucks were banned. In response, Moses promised to place landscaping on the new expressway so it would fit with the park's character. This revised plan garnered