Yes, I think any ancient route of the Elves' Great Journey would correspond to what is called the Great Forest Road, which then was supposed to link up with the East-West road of Eriador, assuming Orks did not hold the pass against you.
I must revise my last post, in that reading The Illustrated Hobbit (excellent) to my daughter, I see that it is Beorn (not Gandalf) who reports how marshes had encroached on the Eastern End of that Road.
Despite his certitude in this regard, Beorn also submits other reasons for the Dwarves not to go that way. So, one may assume that the marshes alone were not an absolute barrier, and not necessarily a very longstanding one.
Presumably, the Old Forest Road was very broad and in that way was not easily overrun by the evil power infecting Mirkwood.
The Elf-Path was a creation of Thranduil's peoples to be sure, and not too ancient, and it was protected by Magic as a way for those Wood Elves if needed to still to send messages westward.
Aside from the Elves' prickly ownership of the path, for large groups or commerce, it would have been very inefficient. The chapter "Flies and Spiders" indicates that it was narrow and "wound in and out among the trunks." I would further submit, given the slowness of Thorin & Co. there, that it also weaved back & forth on a larger scale not readily apparent to the Dwarves in the gloom, but still too fine to be represented on the Wilderland map. This may have been part of a trade-off associated with the enchantment that kept its slender course immune from Mirkwood effects.
As for the Old Forest Road, I would surmise that later with the Rise of Dale and the organization of Men by Beorn, the Old Forest Road was fully restored and kept relative safe for travel, and that that was how movement between the Lonely Mountains and the Western Lands was undertaken after Bilbo's adventure. Alternatively, perhaps, the route around the Northern End of Mirkwood remained passable, but even if so, I'd think the Old Forest Road also became a relatively more useable and regular means of commerce.
Bilbo's adventure seems to have caused or related to the deminishment of a lot of evil in those regions. And, even if a feigned retreat for Sauron, his leaving Dol Guldor probably meant that the Necromancer's evil influence and threat was more contained from North.
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The hoes unrecked in the fields were flung, __ and fallen ladders in the long grass lay __ of the lush orchards; every tree there turned __ its tangled head and eyed them secretly, __ and the ears listened of the nodding grasses; __ though noontide glowed on land and leaf, __ their limbs were chilled.
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