WNYC has learned that the city Department of Transportation is quietly considering a plan to open parts of the city's parkways to small trucks. WNYC's Andrea Bernstein reports.Parkways were originally designed for pleasure driving, and current rules exclude all commercial vehicles. But the city has commissioned a study to manage increasing truck traffic. And along with more clearly demarcated truck routes and better enforcement, the report recommends moving some trucks to parts of the Belt, Henry Hudson, and more of the Grand Central.The parkways would only be open to trucks under 8000 pounds -- about the size of two SUV's. But the DOT study says about half of all truck traffic in the city comes from small trucks and delivery vans.The suggestion is drawing mixed reactions. A group representing the Henry Hudson Parkway says the parkways should be inviolate and opening up parkland to trucks will only encourage more truck traffic. But Transportation Alternatives agrees with the DOT, saying parkways are akin to highways, and that its better to have trucks on parkways than driving through local streets. The NY Automobile Association says it has "reservations" about the proposal, noting on ramps and lanes would have to be widened.All the organizations propose a cross harbor freight tunnel as a long term way to reduce truck traffic in New York city. The DOT is holding community meetings on the plan and will finalize proposals in the fall.