@Stevig: If you need webspace, mysql and PHP access, I can provide you wish an account on my webserver (the same as Satish uses for VOICES). Currently I have about 140 Gb of free space on my server, so space is not a problem.
Obviously the key to a successful interface is to keep the amount of data transferred to a minimum. The client (VOICES) already has the maps, so no maps would need to be transferred. Obviously some method of parssing websites would be needed, and each new website added would need it's own parser.
I know for the UK, Route 66 application has an 'update traffic' button. You may want to sniff / Etherreal the communication with the Route 66 server. I presume it's eithere an FTP or HTTP pull. You could then use the same data format for communication as them. Route 66 software can be found at
www.66.com If you need some Ethereal trace I can get that for you.