contacting panel of experts

For my three panel of experts, I was thinking of asking someone from the department of public works, municipal transportation agency, and an graffiti artist. I already have some people in mind for the graffiti vandal. I'm still waiting to hear back from the other two by email. Here are some links that will take you to Muni and dpw's main websites. 

http://www.sfmta.com/cms/home/sfmta.p 

http://www.sfgov.org/site/sfdpw_page.asp?id=33011

The Muni website wasn't very helpful with gathering information for my research. When searching with key words 

on the site. A few things show up but barely enough information to use. The dpw was a lot more useful, it provided

background information about the department and what they are trying to accomplish as a community volunteer group.

While I wait for these groups to email me back with more information. I will being at the library trying to find some books

that might give some info on not only graffiti in general but bus tags/graffiti/vandalism.