Maltby junction on the San Ramon Branch of the Southern Pacific

[markpierce]

Can anyone provide me any info about Maltby junction, where the Atchison Topeka and Santa Fe crossed the (now former) San Ramon Branch of the Southern Pacific? In particular, what facilities/mechanisms existed there to protect the crossing during the time the branch was operating, and what exists now. Maltby junction is about a mile south of Avon. Avon is about three miles east of Martinez, California where the branch connected with SP's Mococo line running from Martinez to Tracy.

I do possess Irma Dotson's excellent book San Ramon Branch Line of the Southern Pacific, but none of the text or maps provide any information on the junction. Topographical maps show the northern remnant of the San Ramon branch crossing the ATSF (now BNSF) mainline, but there are no public roads in the area to gain access because the place is now smack in the middle of a petroleum refinery.

[markpierce]

I've been informed that the ATSF line drops into an underpass with the SP crossing the ATSF with a bridge. So, there was no traffic conflict.