Is there any rule at all for the stress of compound words?

I find the stress of compound words very confusing because the stress can fall on either word of a compound. Someitmes it is on the first word, sometimes it is on the second word. I was wondering whethere there are any fast rules at all for the stress of compound words in English?

example words with stress falling on the first word:
emergency brake, main road, negotiating table, news release...

example words with stress falling on the second word:
emergency services,emerald green,new wave, office hours...

I think "main road" and "office hours" can be pronounced either way. But you're right, there does seem to be some kind of arbitrary variation here. I don't think there really is a simple rule, but you'll probably get it figured out if you keep listening.

I think the general idea is that the more important word tends to receive more stress, but of course that can be a subjective and arbitrary judgement at times.

- Kef

At least here, compound words always have their overall primary stress on the primary stress of the first component word. There are cases which differ from these, but in reality all the component words before the word with the overall primary stress are acting as adjectives rather than as members of a compound noun.

Here's how I pronounce those words (using initial ' for primary stress and initial , for secondary stress):

e'mergency ,brake
'main 'road
ne'goti,ating ,table
'news re,lease

e'mergency 'services
'emerald 'green
'office ,hours
'new 'wave

As you can see, many of those words, at least in my speech, take a double primary stress.

I'd usually stress "office hours" on the word "office". I'm not sure what rules there are, if any (like so many things in natural languages).

The only rule is that your audience understands what you are saying.

All can fall either way...
In the case of "emergency brake", if you're discussing several different types of brakes ("anti-lock brake", "hand brake", "foot-pedal brake", etc) the stress would be on the first component--"emergency" to distinguish it from the others.

In the case of different types of emergency items, like "emergency handle", "emergency cord", "emergency lever", "emergency number", etc., the stress would then be shifted to the differentiating component--the second one.