CSX Signal Rules Go Canadian

In September of 2024 CSX added two new signal rules to its rulebooks, Limited Approach Limited and Limited Approach Medium, and examples of both are just starting to appear in the field. In fact I believe this is the first use of a non-cab signal related multiple lamp flashing signal in the United States. If these rules and multi-flash aspects sound both strange and familiar at the same time its because these sort of "combination" signal rules are a standard thing north of the border in Canada. 

Since the steam era our friends up north have taken the concept of speed signaling to a bit of an extreme with every possible combination of one speed going to another speed given an explicit signal rule. You want to go Slow Speed to Limited and Limited to Slow, Canada has you covered. 

Everywhere else in North America has realized that this extreme amount of signal rules is dumb and will lead to confusion and higher training costs. While some combination indications like Medium Approach Medium or Medium Approach Slow occur frequently enough to be worth including, the remainder are unlikely to see much use and are better off being substituted for (for example downgrading Limited speed combinations to Medium) or covered by special rulebook instructions like NORAC famously allowing trains to diverge over an Approach X type signal indication if the previous signal was not Clear. Anyway it looks like CSX has thrown its lot in with the Canadians and started to care that trains keep that extra bit of Limited Speed when diverging back to back. 

Limited Approach Medium was spotted at on A-Line at SOUTH MICRO where southbound Amtrak Carolinian Train 79 will make an early divergence to its eventual turn off at SELMA with the NORTH SELMA crossovers in between. While the NORTH SELMA crossovers are Medium Speed, T79 would be taking a straight route there so many they just wanted to get it slowed down early for the tight turn onto the H-Line an additional mile beyond. Youtuber Danny Harmon managed to catch a Limited Approach Limited at 10TH ST interlocking on the Vitis Sub. He was also puzzled as to the purpose as the next two signals in the northbound direction were intermediates at standard 2 mile intervals. 

Anyway if you would like my opinion of these new signal rules, necessity aside CSX did a good job picking from those signal aspects that were available to them. Despite CSX's major screw up picking R/Y/G as Medium Approach Slow, which forced Medium Approach Medium to use R/Y/*G*, that mainly presents a problem for a potential Medium Approach Limited. Using R/*Y* for these Limited Approach X signals jives with CSX choice of R/*Y* for Limited Approach. Thus we have Rule 1281-D R/*Y* Limited Approach, 1281-E(?) R/*Y*/G Limited Approach Medium and Rule 1281-F(?) R/*Y*/*G* Limited Approach Limited. (Note I could not determine the actual CSX signal rule numbers at this time so those are my best guesses).