An engineering report dating back to 1961 suggested that building a bypass around the last two mainline tunnels was the best way to solve the congestion. The Commission awarded three contracts to construct the bypass from July 1966 to March 1967. The contracts cost $17.2 million for roadway and another $2.5 million for construction of a new Sideling Hill Service Plaza to replace the Cove Valley Service Plaza, which was along the to-be-bypassed alignment. The $2.5 million project was to include ramps from both directions to the service plaza, so it could serve both directions. The style of the tunnel bypass was to follow the same style as the Laurel Hill bypass. On November 26, 1968, the three twinned tunnels opened, and the bypass of the Rays Hill and Sideling Hill Tunnels opened. The new bypass also opened the Breezewood Interchange and the number of lanes along the turnpike expanded to four (two in each direction) or five (two in each direction, plus a climbing lane going uphill).