The Regional Plan Association has a new study warning that Metro-North’s infrastructure is falling apart, and demands $3.6 billion in immediate spending on state of good repair. In general, my line on deferred maintenance is “you mean the agency deferred maintenance all those years and didn’t tell us?”. But in this case, despite the language, most of the proposed spending is improvements, namely rehabilitation or replacement of old movable bridges with low speed limits, rather than ongoing maintenance folded into long-term capital spending.
$2.8 billion of the proposed program is for replacing five bridges: Pelham Bay, Cos Cob (over the Mianus), Walk (over the Norwalk River), Saga (over the Saugatuck), and Devon (over the Housatonic). I believe all five should be replaced in the medium term, but the cost proposed is much higher than it should be. $560 million per bridge is quite high, and out of line with Amtrak found on PDF-pp. 29 and 56 of the Northeast Corridor Master Plan. Amtrak cites the cost of replacing the Pelham Bay Bridge alone at $100 million, and the cost of both replacing it and modifying curves on the Hell Gate Line at $500 million. It cites the cost of replacing both the Saga and Walk Bridges at $600 million.
Now, the RPA lists Saga as the easiest bridge to replace since it’s two two-track bridges, so work can be done one bridge at a time with less disruption to ongoing service, but conversely Pelham Bay is also quite cheap according to Amtrak.
But there’s a more serious problem, which is the avoidance of talking about service plans for commuter and intercity rail. If there is serious effort at adding Metro-North service to Penn Station or at raising intercity rail speeds, then the worst speed and capacity restrictions should get priority, and the infrastructure construction should be based on what promotes the desired service plans. It is very expensive and probably cost-ineffective to six-track everything from New Rochelle to Stamford, to allow three speed regimes: local, express, and intercity. I have argued before that it’s better to leave it at four tracks and bypass bad curves, around Port Chester, and make this the six-track segment. This is of course independent of maintenance issues, but suggests which bridge replacements are necessary to support these bypasses (Cos Cob) and which aren’t (the rest are less critical, especially Walk, which intercity trains should bypass on a straighter I-95 segment).
Likewise, there’s a capacity crunch west of Stamford but not one east of Stamford, and this again suggests Cos Cob as the most important priority. Finally, the slowest segment of the NEC away from immediate station areas is the western corner of Connecticut, from the state line to Stamford; Stamford’s curves are mild, while those heading out of Port Chester all the way across the Mianus are quite bad, and straightening the segment would also require straightening the bridge, which can be done easily if it’s replaced. Despite all this, the RPA and Amtrak are saying Cos Cob needs rehabilitation and not replacement, which misses opportunities to both improve reliability and speed up a slow segment.
Moreover, there is no mention of grade-separating Shell Interlocking, just south of New Rochelle. While not a state of good repair issue even in theory, the interlocking’s tight curves impose a limit of either 30 or 45 mph (so, 50-70 km/h), depending on source, in an area that could otherwise support 200 km/h or more. It is very difficult to straighten New Rochelle to sufficient curve radius for that, but 150 requires only minor takings. This may be necessary, independent of speed issues, to raise capacity enough to allow Metro-North service to both Grand Central and Penn Station. It’s possible to schedule trains through the flat junction, but this imposes an additional constraint on the schedule, on top of track-sharing with Amtrak and, in the East River Tunnels, the LIRR.