Hyphenation in compound adjectives [duplicate]

Possible Duplicates:
To hyphenate or not?
When is it necessary to use a hyphen in writing a compound word?
When is it appropriate to use a hyphen?

In the sentence "Portland is known to be one of the most bike friendly cities in the US", is a hyphen necessary in "bike friendly"? As far as I know, the hyphen is only required when leaving it out would cause ambiguity. Wikipedia uses the example of "a small appliance factory" vs "a small-appliance factory".

As far as I can tell, the sentence above is pretty clear. A quick google search for "bike friendly city" brings up instances of both hyphenated and non-hyphenated usage. Thoughts?

Please excuse the poor formatting, sent from my iPhone.

Solution 1:

The only reason that I'd use 'bike-friendly' in the sentence is that it makes the sentence slightly easier to read IMO - leaving out the hyphen causes my brain to momentarily check that 'most bike' doesn't mean anything, whereas the hyphen removes even the possibility of ambiguity. But that could be just my brain :)

Solution 2:

Comma Sense—a fun-damental guide to punctuation reports the following text:

Often hyphens join two or more words that, taken together, form an adjective. The tin-of-ear among us write three day shipping and eight man crew. But the clear-eared, hearing no pause between the two or more words that make up the modifier, write three-day shipping and eight-man crew, as well as front-office decision, state-of-the-art technology, zero-tolerance approach, and—well, you get the idea.