Longest limited access highway (freeway, expressway) without exit numbers?

[DJ Particle]

Between MA-79, MA-57, MA-28, US-1, and US-44.....  which is the longest Massachusetts stretch w/o numbers?  They're also not getting numbers as per the 2019 renumbering plan.

[TheStranger]

If we're looking at historical answers, the obvious one is I-5 in California before the state used exit numbers (so, up to about 20 years ago)

Somehow, this and US 101 in California both escape the list because both have had at least 4 numbered exits near downtown Los Angeles since 1971!

99 from Wheeler Ridge to Red Bluff might actually be the winner in this category since none of its exits were numbered prior to the 2000s.