As of May 2010, the township had a total of 48.98 miles (78.83 km) of roadways, of which 31.14 miles (50.11 km) were maintained by the municipality, 9.73 miles (15.66 km) by Warren County, 7.89 miles (12.70 km) by the New Jersey Department of Transportation and 0.22 miles (0.35 km) by the New Jersey Turnpike Authority.

Greenwich is accessible from Interstate, U.S. State and County roads.
Interstate 78 passes through in the central area while U.S. Route 22 runs along the western border before running concurrent with I-78.
Route 57 passes through in the north and Route 173's western end starts at the western municipal border at I-78/US 22.

County Road 519 travels through the western corner for a short distance while County Road 579 passes through very briefly in the south before terminating at Route 173.

A small part of the Norfolk Southern Railway's Lehigh Line (formerly the mainline of the Lehigh Valley Railroad), runs through the southern part of Greenwich Township on its way to Phillipsburg, New Jersey.
As of May 2010, the township had a total of 48.98 miles (78.83 km) of roadways, of which 31.14 miles (50.11 km) were maintained by the municipality, 9.73 miles (15.66 km) by Warren County, 7.89 miles (12.70 km) by the New Jersey Department of Transportation and 0.22 miles (0.35 km) by the New Jersey Turnpike Authority.
Greenwich is accessible from Interstate, U.S. State and County roads. Interstate 78 passes through in the central area while U.S. Route 22 runs along the western border before running concurrent with I-78. Route 57 passes through in the north and Route 173's western end starts at the western municipal border at I-78/US 22.
County Road 519 travels through the western corner for a short distance while County Road 579 passes through very briefly in the south before terminating at Route 173.
A small part of the Norfolk Southern Railway's Lehigh Line (formerly the mainline of the Lehigh Valley Railroad), runs through the southern part of Greenwich Township on its way to Phillipsburg, New Jersey.
Greenwich Township, Warren County, New Jersey