Route 10 is concurrent with seven other routes (US 5, US 20, US 202, and Massachusetts Routes 57, 9, 116, and 63) for 43 miles (69.20 km) of its nearly 61 miles (98.17 km) in the state with three points of triple concurrency, leaving less than a third of its length as the sole road designation.
History
An odd sight greeted motorists in Easthampton in July 2005: standard issue Alabama state highway signs with the number 10 in a map of that state, instead of the standard Massachusetts square. This odd "Alabama 10" signage came about when a contractor mistakenly applied the sample from a federal manual. The signs have since been replaced with the correct shields.[2][3]