Interstate 495 (I-495) is an auxiliary route of I-95 in the US state of Massachusetts, maintained by the Massachusetts Department of Transportation (MassDOT). Spanning , it is the second-longest auxiliary route in the Interstate Highway System, being roughly shorter than I-476 in Pennsylvania. Serving as one of two beltways (the other being Route 128) that forms a semicircle around Boston, and being the "outer" beltway, I-495 has its northern terminus in Salisbury, where it splits from I-95. Its route forms an arc with an approximately radius around the city and intersects seven additional radial expressways: I-93, US Route 3 (US 3), Route 2, I-290, I-90 (Massachusetts Turnpike), Route 24, and I-95 once more. I-495 has its southern terminus in Wareham, at the meeting of I-195 and Route 25. Originally, the stretch from Route 24 to I-195 was signed as Route 25, that status now only begins east of I-195. I-495 and areas to its immediate east are often regarded as the inner ring of Greater Boston. The freeway's northern segment parallels the New Hampshire border, at one point coming as close as to the boundary, and its southern end is roughly north of Cape Cod. West of I-495 is the Worcester area and Central Massachusetts. I-495 is a heavily traveled route serving communities in Plymouth, Bristol, Norfolk, Worcester, Essex, and Middlesex counties. Route description I-495 begins as the direct continuation of Route 25 at the intersection with I-195 in West Wareham. It starts as a two-lane highway in both directions. It gets the third lane during the interchange with Route 24. The junction includes the unusual transition of shrinking from the six-lane Route 25 to the four-lane interstate due to the third lane of Route 25 joining to and from I-195. The road heads roughly northwest, passing through the towns of Rochester and Middleborough (where the road meets US 44) as a four-lane highway before entering Bristol County, crossing the Taunton River at Raynham. I-495 becomes a six-lane highway just southeast of the Route 24 interchange (which is actually in neighboring Bridgewater). The road continues northwest through Taunton and Norton before entering Mansfield, where there is a short collector–distributor road concurrency with Route 140. I-495 makes its southern junction with its parent route, I-95, on the border between Mansfield in Bristol County and Foxborough in Norfolk County. The road continues through Plainville (where there is a junction with US 1.