Here's an effort to separate freight signaling from transit, but still has a freight orientation. Question is: who has transit and freight operations sharing a line in some way, and what effect does it have on freight ops?

Per FRA and FTA, which have many rules on the subject, there are 2 basic forms of sharing: r/w without connection (but sharing road crossing gates), and actual connection which may or may not include actually running freight trains on transit lines. The first form is simple - tracks in the same r/w, though whether there's enough physical separation is sometimes a question. Can be some interesting complications when, for instance, FRA changes rules about blowing horns for the crossing and the transit agency hasn't set up a formal "quiet zone" with FRA; things can get noisy for a while. The second form could have signaling and operating implications for both transit and freight, as well as other issues (e.g. time separation as required by FRA) where the transit equipment doesn't meet mainline standards (which is almost universal).

Places I know of in CA (sometimes just by surfing Google Maps; others by personal observation) include:

Sacramento RT:
* Shares r/w with UP Placerville Industrial Lead along Folsom Blvd. and UP Canyon Sub in South Sacramento. Quiet zones throughout now (bells only) except for some reason at Jackson (SR 16).
* Crosses an industrial spur along 7th St. that used to provide access to CSRM.

SF Muni:
* Crosses freight lines at Islais Creek bridge and at Carroll St. (Is Carroll St. still active? Looks like parts of the line have been covered or removed chez Google.)

VTA:
* Shares track with freight spur to Moffett Field.
* Shares r/w with Permanente Branch.

LA Metro lines:
* Blue Line shares a lot of r/w with UP but doesn't appear to have any rail crossings chez Google. Lots of shared road crossings of course.

San Diego:
* Shares track with SDIY to Tijuana and Santee. TT19 shows a street-running part of the Santee ("Orange") line using SDTI Rule 2.1.17 instead of the usual ABS or other methods but doesn't describe that rule anyplace else - references?
* Sprinter shares track Oceanside-Escondido

Anyplace else, at least in the US West? I'm not familiar with the Portland and Seattle systems though of course through this board have heard about WES (which is the oddball with full rail equipment compatibility). Utah - didn't they just open a line with off-hours freight? Probably not in Phoenix. It would seem that the freight people would need to work a little differently when on trolley tracks - how much of a hassle is it?

Cheers

m