The Massachusetts Department of Transportation (MassDOT) is announcing it will be implementing temporary overnight closures of the Callahan Tunnel (Route 1A northbound) in Boston. The closures will take place on Monday, October 24, and on Tuesday October 25, during overnight hours between 11:00 p.m. and 5:00 a.m. the following morning. The closures are necessary to allow crews and contractors to safely and effectively deliver and install new pumps and equipment for the Callahan Tunnel vent buildings. Appropriate signage, law enforcement details, and advance message boards will be in place to guide drivers traveling to Logan Airport and East Boston.  Motorists should follow detour signs through the Ted Williams Tunnel. MassDOT encourages drivers to seek alternate routes, reduce speed, and use caution while approaching and traveling through the area. These operations are weather dependent and subject to change without notice.  For more information on traffic conditions, travelers are encouraged to: • Dial 511 before heading out onto the roadways and select a route to hear real-time conditions. • Visit www.mass511.com, a website that provides real-time traffic and incident advisory information, access to traffic cameras, and allows users to subscribe to text and email alerts for traffic conditions. •  Follow MassDOT on Twitter @MassDOT to receive regular updates on road and traffic conditions. •  Download MassDOT’s GoTime mobile app and view real-time traffic conditions before setting out on the road.Â