FYI, the old I-93/Artery BGS' containing the word X-Way
) read:90-93-3 SOUTH
The BGS closest to the Central Artery itself had an elongated right-turn arrow underneath the message was erected in the late 70s and faced traffic exiting the Sumner Tunnel.
Side Bar: This BGS replaced an older BGS that read: SOUTH
3 EXPRESSWAY SOUTH
Note: the SOUTH 3
signs were placed on the upper-left corner of the BGS and were similar to the trailblazer/assurance type signs. These two signs were likely placed on the main BGS board in the early 70s (when the DPW re-aligned MA 3 onto the Artery & Southeast Expressway.
2 other overhead-mounted BGS displaying identical messages were added in the early 1980s. One gantry was placed just before the Sumner Tunnel entrance, the other just outside of it. All the shields on these 2 BGS' featured the older-style MassDPW fonts and button-copy lettering.
About a year or two after those BGS' were erected, the MTA or DPW revised the messages on the BGS panels directing would-be I-93 southbound traffic to read:93-3 SOUTH
90 Mass Pike
IIRC, the original downward arrow was replaced w/a slightly smaller arrow to allow more room for the above-messages.
Unfortunately, I couldn't find any old pictures on-line that showed these BGS'.
but plenty of businesses refer to 93 as the "X-way". For example, a Shell station on the corner of Mass Ave and Columbus Ave proclaims itself the "Last gas before X-way".
That designer of that sign likely copied the abbrev. term from the fore-mentioned BGS'.