Avoiding the Old Forest...?
 

I'm on my fifth re-reading of The Lord of the Rings (with the intent of moving straight through all of the extended works right after over the course of 2009) For this reading, it's my first with my newly purchased harcover set illustrated by Alan Lee. One thought occurred to me in reading A Conspiracy Unmasked and The Old Forest.

Note: As I'm reading, I am referring to both Barbara Strachey's Journeys of Frodo and Karen Wynn Fonstad's The Atlas of Middle Earth.

When leaving Crickhollow for Rivendell, it's clear that the Hobbits wanted to remain undetected and therefore chose to avoid Buckleberry (the assumed first destination of the Black Riders) and didn't want to be seen crossing the Brandywine Bridge. By necessity Frodo wisely chose to stay off the main road and avoid the North Gate. It's also clear that they are hoping (even expecting) to meet Gandalf on the East Road.

Why then wouldn't Frodo, et al, simply use the Tunnel Gate under the Hedge and---rather than entering blindly into the Old Forest---simply follow the narrow clearing between the east side of the Hedge and the Old Forest. This seems to be not just easier terrain to traverse than the Forest (and even the places where the Forest meets the Hedge would be easier to circumvent via brief sojourns into the woods than to stake their entire jourey through the dark forest) but is also a more direct route to the East Road.

One fear voiced by Frodo is that the East Road near the borders (near the Brandywine Bridge) might be closely watched. But even so, it would be easy enough for the Hobbits to veer east at the northern edge of the Old Forest, still a few miles south of the East Road, in order to pick up the road further along. Doing so would not only have saved time, but would have avoided the troubles of Old Man Willow and the Barrow Downs.

Now, of course I am aware that for the purpose of the story, it's much more interesting to throw the Hobbits into danger and strange encounters. I am just wondering, in such a thought out work, if there could be a reason to justify it within the context of the story?

As the dialogue among the Hobbits as they stood near the gate indicates, they anticipated no real difficulty in getting through the Forest, despite the warning of Fatty Bolger. The cover of the trees might have seemed appealing to them as well.
Also, It doesn't seem that any of them had ever been much beyond the borders, other than into the Forest, and they may not have had a very clear idea of the exact track of the Road after the Brandywine Bridge. They knew though, that going through the Forest and veering east and slightly north was sure to lead them to it.

I thought the hobbits were worried that the Nazgul would break through the gate at the Brandywine Bridge and be waiting for them if they ventured directly onto the East Road.

Well, early on in "Three is Company" Gandalf advises Frodo to travel:

Following the hedge would have been too straight, perhaps.

The same kind of idea has often come to my mind for their journey from Tom Bombadil's house to the Road.

Why didn't they just keep to the eastern edge of the Old Forest ?

Of course, the real answer is that at the time Tolkien had no idea where the story was going, but since Bombadil and Willowman already existed he had ready-made plot to use.

There wasn't even any geography at the time, beyond what he had just invented for the Shire and Buckland. All he had was The Hobbit's vague given of a Road that eventually reached Rivendell. He never actually did get the two books to line up , even though he tried in LR 2d Ed (as Fonstad and CT discuss)- this may lie at the root of his latter-day insistence on drawing the map first!

That might be the answer to why Tolkien wrote it that way. . .but it does not answer why the hobbits chose the rute they did.

I see it like two very different discusions.

Speaking strictly within the confines of the story I agree with this to a large extent, although Merry at least had some ideas that the Old Forest was more dangerous than your typical wood.

It doesn't even seem that any other idea besides plowing right through the wood was considered.

In A Conspiracy Unmasked, Frodo explains that he wants his departure to remain secret for at least a few days, so he suggests going where none would expect a hobbit to go.

Fredegar's response following this adequately sums up what Tolkien wants the reader to know, that most hobbits are deeply suspicious and afraid of the Old Forest, so none would think, even under pressure from the Black Riders, to suggest that Frodo might have gone through the Old Forest.

In other words, they take the least likely route. Interestingly, no one mentions if the Old Forest would be malevolent to those who seek them.

If they stay in the clearing it's quite conceivable
the Black Riders would break in and quickly overtake
them (or come the other way going around and then south
after going past the High Hedge) whereas that's impossible
for horses in the Old Forest. And if you look at the maps by
Strachey or Forstad (if the former is still in print) if you
assume the Old Forest is navigable it's pretty much a
covered, straight path to Bree.

Btw, a possible plot hole is the Bucklanders apparently
being totally unaware (unless I forget references in LOTR)
of Tom Bombadil, especially since he must have been not
infrequently in the eastern Shire rapping with Farmer Maggot
since I can't see Maggot's wife letting him traipse off to some
foreign place across the Brandywine.

Well, I don't know if Bombadil had set foot in the Shire within living memory of any of the Hobbits. His 'country' seems to have consisted only of the Forest and the Downs; and Gandalf (and Tom himself) stated he did not leave the bounds he had set for himself for any reason.
I think it more likely Maggot visited him, especially since Merry noted that he had been known to enter the Forest at one time.

Tom seems to have had the odd Shire-wards excursion...

though admittedly he didn't get such a good reception at Grindwall..

That would certainly seem to put ice on my theory, but I was drawing strictly from LOTR.