Castle Secondary and Christiana Avenue Industrial Track railroad lines, DE 9A, and the Christina River. The freeway passes near another landfill as it comes to the 12th Street exit. The road runs through some marshland, crossing Shellpot Creek and Norfolk Southern Railway's Edgemoor Lead railroad line, before coming to an interchange in an industrial area of Edgemoor that connects to the southern terminus of DE 3 as well as to US 13. Following this interchange, I-495 crosses over Norfolk Southern Railway's Shellpot Secondary and Amtrak's Northeast Corridor railroad lines before it runs between US 13 and suburban areas to the west and the Northeast Corridor and the Delaware River to the east, passing northwest of Fox Point State Park and crossing Stoney Creek and Perkins Run. I-495 continues along this configuration until it reaches Claymont. US 13 heads farther west from the freeway and I-495 makes a turn to the north away from the railroad tracks and the river near Claymont station along SEPTA's Wilmington/Newark Line that uses the Northeast Corridor. The road comes to another exit for US 13 before merging into northbound I-95 at the DE 92 interchange near the Tri-State Mall and the Pennsylvania state line. Southbound I-495 features an exit to DE 92; the remaining ramps of the DE 92 interchange connect directly to I-95. Southbound, the I-495 splitoff from I-95 actually starts in Pennsylvania but crosses into Delaware later before the exit to DE 92. This ramp is inventoried by the Pennsylvania Department of Transportation as State Route 8009. I-495 has an annual average daily traffic count ranging from a high of 105,159 vehicles at the south end of Wilmington near the Christina River to a low of 22,379 vehicles at the ramp to I-95 at the southern terminus. As part of the Interstate Highway System, the entire length of I-495 is a part of the National Highway System, a network of roads important to the country's economy, defense, and mobility. History In 1948, the Wilmington Transportation Study proposed two new roads running between the southern end of Wilmington and the Pennsylvania state line to improve traffic flow in the Wilmington area. Route A followed the current alignment of I-95 through the city while Route B bypassed the city to the east along the current alignment of I-495. In 1956, the Interstate Highway System was created, with FAI-3 proposed along the current alignment of I-495.