Yesterday I was at the intersection of VA 144 and 145, located here: http://goo.gl/maps/HWdKy
Note the railroad crossing just to the west. I was in the left turn lane from northbound Chester Road (VA 144 to the south of the intersection and VA 145 north of it) onto westbound Centralia Road (VA 145 to the west and secondary to the east) when a train passed by. While it was crossing the signals only cycled between traffic going straight in both directions on Chester Road, and traffic going south on Chester Road and turning left onto eastbound Centralia. After the train passed the normal signal cycles resumed. Is this a common thing when a crossing is located near a big intersection?
Yes. Called railroad pre-emption so that vehicles can clear the tracks when a train is approaching, then alter the timing so vehicles can't approach the tracks until the train has cleared.
A similar signal set-up exists at SEPTA's Secane (Upper Darby Twp., Delaware County, PA) train station at the intersection of Providence Road and North & South Avenues.
Aerial View (http://goo.gl/maps/RNFtH)
GSV (http://goo.gl/maps/dZfEi)
During rush hours, I've seen some serious traffic back-ups after the signal cycle is interrupted by a train crossing & stopping at the station.
Side bar: A large, replacement station, relocated further away from the intersection is in the works and should be open in a couple of years. Such should reduce the train-crossing related backups.
We have a few intersections that pre-empt here in Huntsville. Some of them will hold red in all directions while others will hold green with a protected left for the direction coming from the tracks.
They do that in the Portland Metro as well in relation to the MAX and WES systems. The most obvious is in Beaverton at the Transit Center. Hall Blvd. is setup to clear when a train comes, but won't let traffic on TV highway move for a couple of minutes at that intersection, but puts greens on the next several to get away both east and west.
Makes sense so people don't get trapped on the tracks. Despite the signs saying, "Don't stop on tracks", people still do it anyways.
Here's an interesting signal in Arizona that forces people to stop before the tracks.
https://goo.gl/maps/plqPZ
Here's one such setup in Rochester, NY.
https://www.google.com/maps/@43.139518,-77.708644,3a,75y,157.27h,90t/data=!3m4!1e1!3m2!1sPbLo1M0PQKsE0oUJNtTOTA!2e0!6m1!1e1?hl=en
This one has a protected left turn movement for clearing the tracks.
The most common variation I've noticed is to have an adjacent intersection flash all-red. Sometimes, the road that the tracks do not cross might flash yellow, but in that case there has to be some means of discouraging people from turning across the tracks. One way is to have an illuminated "No Right Turn" sign with a flashing light over it, or, more recently, have an LED (or fiber-optic?) of a white right turn arrow in a red circle. Another way is to have a right turn signal signed "No Turn on Red", which stays red for the duration.
Some signals will have an extra face before the tracks on the non-intersection side. While these might be used to turn red ASAP on a train signal (thus preventing motorists from stopping on the tracks), I've known at least one to always turn yellow and red a few seconds before the one at the intersection, for extra safety.
Quote from: steviep24 on April 20, 2015, 04:28:25 PM
Here's one such setup in Rochester, NY.
https://www.google.com/maps/@43.139518,-77.708644,3a,75y,157.27h,90t/data=!3m4!1e1!3m2!1sPbLo1M0PQKsE0oUJNtTOTA!2e0!6m1!1e1?hl=en
This one has a protected left turn movement for clearing the tracks.
That's exactly the one I expected to find before clicking the link. ;-)
It also has a "No Turn On Red" aspect on the intersecting road that illuminates only when the crossing signal is activated. (That also explains why the cross street has a protected left turn arrow.)
I have a crossing in the middle of the intersection near where I live. What's nice is the signals gives priority to the busier of the two streets, but on a shorter cycle so that the other road can clear out. Once it finishes that cycle, the signals go back to a normal cycle until a train comes back again