Salt lake City:

"Traxx" Light Rail System:
shares trackage on two different lines, with freight railroads - on a time separation basis. Most of the system is on private r.o.w., operated under a very basic 3 aspect (2 block) ABS system, same as any other old fashioned double track system would. The only difference is that interlocked crossovers are available in a limited number of locations, permitting wrong track running at speed (one train at a time - no following moves).


"Front Runner" diesel commuter line:
shares r.o.w. with Union Pacific main lines for all but a couple of their approx 90 mile system. They also directly share the same tracks for a few miles north of Ogden
(ex-D&RG south of SLC; UP North Platt line to the north)

Current plans are to extend shared trackage all the way to Brigham City on the north, with talk of limited service eventually to Logan; and shared r.o.w. to Payson to the south. That would then be roughly 155 miles of shared r.o.w. and shared trackage. Also of note; 100% of the existing 90 miles of shared r.o.w. were built as quiet zones; which applies to all UP trains on the r.o.w. as well.

Though diesel powered, the front runner runs like a transit line, with frequent regular service in both directions all day long (roughly 50 trains a day in each direction). They also use modern microprocessor based semi-automatic train control, with similar train control hardware as that used by 70% of freight railroads. The only difference is that the UTA has taken full advantage of all the inherent capabilities of this hardware; whereas, the freight railroads using the same hardware, have not, for the most part done so.

They could have, with not a lot of extra money - as the capability is already built in. I proved that during my 40 years in the business - hands down. With the advent of modern microprocessor signalling, and its inherent capabilities, the differences between freight railroad signalling and transit signalling are indeed blurring. Have been for years. After-all, both are 100% subject to the same laws of physics, so similar solutions can be applied. It is only a few unique issues found in each, that require differing solutions. Nevertheless, microprocessor based signalling can do it all. At the same time even!