So yeah, virtually everyone agrees that rams don't do anything and that walls are too good. The main problem is that you can't keep the ram alive while it dries. Shortening the drying period has it's own problems, of course, since walls won't do anything then. I also heard proposals to bring back brickbashing, with which I don't agree because I think defender needs to have some warning, but also because strength has more than enough uses as it is. Now, onto the actual proposal.
The traps would do nothing but block movement, essentially making a quasi-invisible wall. The idea of course is to use this wall to protect your ram.
Instead of Adventure->Destroy, traps are destroyed by disarming them. This is accomplished with a successful check vs the trap setter. I'm thinking something like sqrt(defusal kit q * sqrt(int * dex)) vs sqrt(trap q * sqrt(int * dex)). Here we're taking a break from the str race and replacing it with dex and int race, which while admittedly is kinda boring (all stat races are) is IMO better than brickbashing. Int and dex are used because int doesn't have much use after 150 or so and dex has no use whatsoever for a fighter (don't you just hate it when you get dex from that one mussel?), and they seem appropriate flavour wise. Dex is also kinda hard, since there's no dex cheese, and I think this is a good thing. As with brickbashing, this would give advantage to larger groups, but I don't think that forcing people to cooperate is necessarily a bad thing. The main difference from brickbashing is that you still get your warning period, even if you can't get to the ram, so there's time to save your important stuff before your walls are broken. It's also not a "you must be this tall for this ride" mechanic, unlike brickbashing, as it works at all stat and material q levels given roughly equal opposition, and IMO all mechanics should work similarly across all levels.
To attempt to disarm a trap, one must first detect it. This could use a per*exp vs int*stealth check, to give some much needed boost to stealth and hopefully make "rogues" a needed element in armies, for some more diversity in character specialization (currently everyone and his grandma is just pushing str, con, agi and UA).
It shouldn't be possible to spam disarming attempts. I think this can be accomplished by giving a Broken Finger debuff on failed disarming attempt, which would set the character's dex to 1 for 24h.
To prevent people from walling their whole villages with traps, they should be pricey and have a limited lifespan. Give them a longish build time, too, so their use in battle is limited, unless you can prepare the field beforehand.
Well, that's it, feel free to point out any gaping holes I missed. And yes, I know, this is a band aid solution. But given the development time it'd take to completely rework the siege mechanics, I think this is a good band aid for the time being.