Art / Graphic design for public transit

If you're like me, one of your favorite parts of see­ing new cities is check­ing out the logo(s) of their pub­lic tran­sit sys­tem. Nowa­days you don't even need to trav­el to these cities to appre­ci­ate their vari­ety; here's a site with an amaz­ing­ly thor­ough cat­a­log.