 In all, I-93 has 48 numbered exits in Massachusetts, although several numbers are skipped in and near Boston.One noteworthy reason that some exits were removed from I-93 is to further address traffic problems in addition to converting the Central Artery from six to eight to ten lanes, by reducing the combined number of on- and off-ramps from 27 to 14.Exit 48 in Methuen, just before the New Hampshire state line, is the highest-numbered exit along the entire route.