A highway and a railroad sharing the same tunnel bore. It seems like it would be practical but I can’t recall ever seeing it done. The railroad tunnel is passing through a mountain ridge and I wondered why not have a road go through the same bore.
Here is a list of said tunnels, the one in Alaska was originally railroad only and the only ways to get vehicles from Whittier to Girdwood was to put them on flatcars and transport them. They widened the bore on the tunnel after I left Alaska in 1995.
https://en.wikipedia.org/wiki/List_of_road–rail_tunnels
Rick J
In the age of steam thick smoke would be a issue and the diesel era would be the fumes.
In the steam era it was not uncommon for the engineer,fireman and head brakeman to cover their mouth and nose with a wet rag while going through a long bore.Diesel crews shut the windows.
The Yerba Buena Island Tunnel (I-80 San Francisco Bay) is a two leval tunnel. As built the upper level was a highway (EB and WB) for autombiles only. The lower level had two Interurban railroad tracks and two lanes (one each direction) that trucks were required to use but were also legal for autos.
After the demise of the trains it was rebuilt as a highway only tunnel EB on lower level, WB on upper level.
Based on what you posted, it seems like it was a rare practice.
I subscribe to the idea that it is my railroad and I make the rules but one of my rules is not to put things on it that were rare or never done in the prototype world.
Although shared road/rail tunnels, such that the road and the railroad share a common right of way vs side by side ROW in a common tunnel tube (like the Oresund Bridge tunnel approach) or is transit related like the Seattle tunnel.
Perhaps a combined road-rail bridge would work? They are more common, although still a bit rare.
Similar to the Whittier Tunnel in Alaska, there are tunnels in the Alps that provide flatcar trains to transport cars and trucks. My family road the train through the St. Gotthard tunnel with our 64 Belair wagon and a pop-up camper in 1972.
Here’s a pic from on the train, nrthbbound.
The Atlantic Avenue tunnel in Brooklyn, NY had a railroad on one side and horse-drawn carriages on the other. It was built in 1844 and closed les than 20 years later, long before motor vehicles were invented. Until recently, it was open for tours.
There was one within Inland Steel in East Chicago Indiana. It went from plant 1 to plant 2 under the road and the PRR main when it existed. Traffic lights controlled traffic and trains. A very scary trip the first time.
Not sure if this is a road next to the tracks, or just a space left where a second track was torn up.
Looks like that tunnel was doubled tracked at one time…I suspect the tire tracks was from ATVs.
Those fake “vintage” pictures can be misleading.
From a safety standpoint I would think a dual-purpose tunnel - where auto and train use the same bore - would be a REALLY bad idea - especially in the event of a crash inside the tunnel from the larger of the two. Dual-bore (separate) tunnels - yes; single-bore - no.
Tom