In message , at 15:43:26 
on Thu, 31 Jul 2008, David Cantrell  remarked:
>> Why over-complicate it? Just have a GPS that shows routes *without* low
>> bridges, that are recommended for use by buses. Then you can avoid other
>> nasties as well.
>
>And you think bus companies would buy that instead of buying the cheaper
>consumer version?

This was a choice between two different specialist GPS designs, to fix a 
specific hazard; not a choice between a specialist and a consumer 
edition.

>> And otherwise it's not failsafe (maybe there's a low bridge somewhere
>> that didn't make it into the gazetteer).
>
>That's not failsafe anyway.  What if a low bridge is built over one of
>your routes?

I'd be a bit surprised if you could get planning permission to build a 
new bridge that's too low for a bus, over an existing street.
-- 
Roland Perry