Editing Interstate 93 (section)

===Massachusetts===
{{see also|Central Artery}}
[[File:End Interstate 93 in Canton, MA.JPG|thumb|left|Southern terminus of I-93 at I-95 in [[Canton, Massachusetts]]]]
I-93's southern terminus is at exit&nbsp;26 (formerly exit&nbsp;12) of [[I-95]] in [[Canton, Massachusetts|Canton]], cosigned with [[U.S. Route 1|US&nbsp;1]] north. At this junction, I-95 north heads to the northwest (cosigned with US&nbsp;1 south, as well as [[Massachusetts Route 128|Route&nbsp;128]], which begins at the interchange), to serve as the beltway around Boston, while I-95 south runs by itself southwest through Boston's southwestern suburbs toward [[Rhode Island]]. The southernmost {{convert|3|mi|km|spell=in}} of I-93 run east through Boston's southern suburbs, passing through Canton and [[Randolph, Massachusetts|Randolph]]. In Randolph, I-93 meets the northern end of [[Massachusetts Route 24|Route&nbsp;24]] (Fall River Expressway/AMVETS Memorial Highway) at exit&nbsp;4. I-93 continues east into [[Braintree, Massachusetts|Braintree]], interchanging with [[Massachusetts Route 3|Route&nbsp;3]], the major freeway linking Boston to [[Cape Cod]], at exit&nbsp;7 (known locally as the "[[Braintree Split]]"). Route&nbsp;3 north joins I-93 and US&nbsp;1, and the highway turns north toward Boston. These first {{convert|7|mi|km|spell=in}} of I-93 follow what was formerly part of Route&nbsp;128 before it was truncated at the I-95/I-93 junction.

[[File:Boston Signs.jpg|thumb|Signs in the [[Financial District, Boston|Financial District]] of [[Boston]] pointing toward [[Downtown Crossing]], [[Chinatown, Boston|Chinatown]], I-93, and I-90]]
Upon turning northward, the highway is known as the Southeast Expressway, passing through [[Quincy, Massachusetts|Quincy]] and [[Milton, Massachusetts|Milton]] before crossing into the city of [[Boston]] over the [[Neponset River]]. After the [[Massachusetts Avenue (metropolitan Boston)|Massachusetts Avenue]] connector exit, the highway officially becomes the [[John F. Fitzgerald Expressway]], also known as the [[Central Artery]], and passes beneath Downtown Boston. A major intersection with the [[Massachusetts Turnpike]]/I-90 (exit&nbsp;16, formerly 20) takes place just south of Downtown Boston. After the massive interchange, motorists use the [[O'Neill Tunnel]] to travel underneath the city and then use the [[Leonard P. Zakim Bunker Hill Memorial Bridge]] to cross the [[Charles River]]. Two exits are located in the tunnel, where the speed limit is {{convert|45|mph|km/h|abbr=on}}. [[Massachusetts Route 3|Route&nbsp;3]] leaves the Artery just before the Zakim bridge via exit&nbsp;18 (formerly 26), and US&nbsp;1 leaves the Artery just after the bridge, via exit&nbsp;19 (formerly 27) (no southbound access). From Boston through the rest of Massachusetts, [[Concord, New Hampshire]], appears as the control city on northbound overhead signs. The Artery ends as I-93 continues north out of the city.

I-93 continues through the northern suburbs of Boston, coming to a second interchange with I-95 and Route&nbsp;128, which run concurrently. Travelers going north can either change over to I-95 north to eventually reach [[Maine]] or remain on I-93 toward New Hampshire. Farther north, in [[Andover, Massachusetts|Andover]], I-93 meets [[Interstate 495 (Massachusetts)|I-495]], providing access to [[Worcester, Massachusetts|Worcester]] to the southwest and New Hampshire's [[Seacoast Region (New Hampshire)|Seacoast Region]] to the northeast. Just south of the state line, I-93 crosses the [[Merrimack River]] into [[Methuen, Massachusetts|Methuen]], where it intersects [[Massachusetts Route 110|Route&nbsp;110]] and [[Massachusetts Route 113|Route&nbsp;113]] at exit&nbsp;43 (formerly 46) just north of the river crossing. Between 2014 and 2018, the Route&nbsp;110/Route&nbsp;113 junction beneath I-93 was converted from a [[Roundabout|rotary]] to a [[partial cloverleaf]], with the new traffic patterns opening in various stages during 2016 and 2017.<ref name="Methuen Rotary Completion">{{cite web |title = Methuen Rotary Project: Major Milestone Reached |url = https://blog.mass.gov/transportation/massdot-highway/methuen-rotary-project-major-milestone-reached/ |website = MassDOT Blog |publisher = Massachusetts Department of Transportation |access-date = October 22, 2020 |archive-date = October 21, 2020 |archive-url = https://web.archive.org/web/20201021201240/http://blog.mass.gov/transportation/massdot-highway/methuen-rotary-project-major-milestone-reached/ |url-status = dead }}</ref> On I-93 northbound, the exit was split into 43A (formerly 46A) for Route&nbsp;110 and Route&nbsp;113 eastbound, and 43B (formerly 46B) for Route&nbsp;110 and Route&nbsp;113 westbound. I-93 then interchanges with the western end of [[Massachusetts Route 213|Route&nbsp;213]], a connector between I-93 and I-495. I-93 then crosses into [[New Hampshire]] after about {{convert|1|mi|km|spell=in}}.

In all, I-93 has 46 (formerly 48) numbered exits in Massachusetts, although, before the [[Mileage-based exit numbering|mileage-based exit numbering system]] was implemented in 2021, several numbers were skipped in and near Boston. Several exits were removed from I-93 to address traffic problems in addition to converting the Central Artery from 6 to 8 to 10&nbsp;lanes, by reducing the combined number of on- and offramps from 27 to 14.<ref>{{cite web |url = http://www.massdot.state.ma.us/Highway/bigdig/facts_figures.aspx#traffic |publisher = [[Massachusetts Department of Transportation]] |access-date = September 25, 2014 |url-status = dead |title = The Central Artery/Tunnel Project - The Big Dig - Facts & Figures |archive-date = June 13, 2011 |archive-url = https://web.archive.org/web/20110613134450/http://www.massdot.state.ma.us/highway/bigdig/facts_figures.aspx#traffic }}</ref> Exit&nbsp;46 (formerly 48) in Methuen, just before the New Hampshire state line, is the highest-numbered exit along the entire route. I-93 once had only 22&nbsp;exits prior to the rerouting of I-95 onto [[Massachusetts Route 128|Route&nbsp;128]].<ref name="I-93 photos">{{cite web |title = Alps' Roads I-93 Photos |url = http://www.alpsroads.net/roads/ma/i-93/6.html |publisher = Alps' Roads |access-date = November 18, 2012 }}{{self-published inline|certain=yes|date=May 2022}}</ref> Nearly the entire length of I-93 in Massachusetts carries four lanes in each direction. Average daily traffic volumes on I-93 in the state range from 100,000&nbsp;vehicles at the New Hampshire border<ref name="I93">{{cite web |url = http://www.mhd.state.ma.us/traffic.asp?f=&C=RTE.I-%2093 |publisher = Massachusetts Highway Department |title = Traffic Counts for Rte. I-93 |access-date = September 14, 2008 |url-status = dead |archive-url = https://web.archive.org/web/20090721002141/http://www.mhd.state.ma.us/traffic.asp?f=&C=RTE.I-%2093 |archive-date = July 21, 2009 }}</ref> and 150,000&nbsp;vehicles at the southern end at I-95<ref>{{cite web |url = http://www.mhd.state.ma.us/traffic.asp?f=&C=RTE.%20%201%20%26%20I-%2093 |publisher = Massachusetts Highway Department |title = Traffic Counts for Rte. 1 & I-93 |access-date = September 14, 2008 |url-status = dead |archive-url = https://web.archive.org/web/20120210024829/http://www.mhd.state.ma.us/traffic.asp?f=&C=RTE.%20%201%20&%20I-%2093 |archive-date = February 10, 2012 }}</ref> to over 200,000&nbsp;vehicles through Braintree and Quincy.<ref name="I93" />