The RAS aspect system does have distinct aspects for Slow and Restricting, (298C and 298D). I imagine this choice was made because those two rules can have the same speed code - although I believe it is allowable to get up to 30 in the cab if the signal displays slow, that might be a recent change.
While Slow proceed, Restricting Proceed and Restricting (bonus points if anyone can correctly explain the difference between the two) do exist, I have yet to see a slow proceed in the field and I haven't yet had an explanation on when the signal would be displayed. For the most part its Proceed, Restricting and Stop Signal.
This may be an actual advantage of the RAS system (or Rule 410 area in general): The ASC speed downgrades are computed to give the highest safe speed for the longest allowable time/distance - which helps throughput. Observant engineers will tend to "preact" to the code change points that they encounter every day, which leads to very smooth operation. I can't think of any system that makes a less talented Engineer drive better...
Those two things contradict in my experience, as a quick example, the curve on the Atlantic Branch into Hall interlocking is good for 30, and is protected by the ASC. You get a 30 code well in advance of the point of restriction such that you are at 30mph before you reach the baseball field, well outside of normal braking distance. On top of that, if you want to run a smooth train you have to slow before you reach the impedance box, in reality this just leads to slower operation. It's not 'better' driving, it forces ultra conservative operation which costs OTP. If the code points were 100% synced to braking distance, then maybe. As it stands they are set for the worst performing train which negates the advantages in agility the MU fleet has. Another thing to consider is that if the speed of the curve does not match what the ASC can present you automatically leads to an inefficiency, in a diesel most curves will code you to 38mph, even if its good for 50. So the system is not set on millimeter precision and you often have to go well underspeed to avoid being penalized by it. NYCT let this issue go too far. Hopefully PTC will be designed to avoid some of these issues.
DaveBarraza wrote:Agree that any hard braking could result in "passengers-off-balance." This is not unlike the current situation in Rule 410 territory which has existed on LIRR for some time, no? (possibly why the beers used to be served in a cup with a straw?!?)...
To address the point of 410, and the real detriment of blind driving is that the Train is driving the Engineer who becomes a passive participant in the safety of the equipment. In a lot of situations it is detrimental to the equipment to allow the brakes to apply in full service. In adverse conditions the wheels will lock up, or at the very least cause a slide. The fact that an Engineer cannot always anticipate a code drop and will get a harash application is what contributes to flat spots and fleet shortages.
In 410 straight run territory you have your time table and the signal at the last interlocking to give you an inkling of whether the ASC drop is a code drop, or train ahead based on that anticipated traffic.
With RAS there is no way to know if the 40 code is setting up a diverging route or if the block ahead is occupied, so you have to assume the worst and the Engineer, in an attempt to run a smooth train and not have constant severe braking (more flat spots) will hang back.