Saturday, September 19, 2009

Baked Bean Breakdown

Another day, another high-speed rail analysis. Designing a line for Massachusetts was difficult for two reasons. In the eastern third of the state, sprawl is almost continuous. In the western half, there is again sprawl around Springfield, and then an area of very jumbled geography. None of the mountains are particularly high, but at the same time there are no large, level valleys that can be used to approach the highest peaks. Anyway, in the eastern half or so, the best solution was to parallel I-90. Following the current CSX alignment wasn't possible because it runs through the center of so many towns. In the west, because of the built environment west of downtown Springfield, a detour to the south was necessary. After that, it was a matter of finding the least bad route until the rail line could meet up with I-90 again. To keep speeds up, several tunnels and viaducts were needed.

I think the main takeaway from this exercise is how restrictive the sprawl around American cities can be on new transportation construction. Most existing rail lines were first laid out in the 1800s, and the Interstate Highway System was planned in the early 50s, when the population was half of what it is now, and much less suburban. Projects planned now, unlike those other two, have to deal with a built environment that is fully built up within a 20 mile radius of large city centers. And large city centers are where high speed rail lines need to go.


Ari said...

Eastern Mass is a bit more complicated than "put it down the Pike."

First of all, from Boston to 128, there is not much room for more trackage without major roadway reconstruction (a third could probably be squeezed in, a fourth less likely). In addition, the air rights, particularly in Newton Corner, would have to be dealt with, where buildings were built over the roadway. The line has several freight trains and a couple dozen commuter runs a day, which are not highly compatible with HSR, although faster service could probably be intermingled, even during rush hour. (The state does want to run more service on the line.) This whole section was originally four tracks, but land and stations were sold to the Turnpike Authority in the early 1960s to build their Boston extension, and only two tracks were retained. One the plus side, the whole line was grade-separated in the 1890s, so faster speeds may be possible.

West of 128, the old ROW was not reduced, and rebuilding it to four tracks would not be a major issue. In addition, it is grade separated until downtown Framingham, where there are two busy grade crossings. A tunnel or viaduct would be helpful/necessary here. The original ROW then continued as a three track main line to Ashland, where it became two.

From Ashland (25 miles from Boston) west, the ROW is two tracks, with grade crossings and curves and hills. However, it is mostly grade separated and tends to avoid town centers, so adding trackage would be possible; the MBTA has proposed doing just that to increase capacity east of Worcester. It would be nice, in addition, to reroute the line west of Lake Quinsigamond, which is currently curvy and indirect (A tunnel, for instance, from Franklin Street to Hamilton Street).

With such improvements, run times from Boston to Worcester could probably be lowered to near 30 minutes with top operating speeds of 110 mph, perhaps a bit higher on some of the longer grade-separated stretches.

(The Mass Pike ROW, FWIW, is generally far too hilly for rail traffic, with several 4-6% grades, so tunneling would be necessary. It also winds up several miles south of Worcester, although there are highway and rail ROWs in to the city.)

(see continuation below, apparently I typed too much)

Ari said...

A great resource is a c. 1950 track chart of the whole Boston and Albany route.

Finally, beyond Worcester, I'm not sure of the benefit of a line to Springfield. New England is small enough that any analysis needs to focus on multiple states. Fast service to Springfield would be nice, but a proper HSR link to New York City would be better. My idea is to run, using some abandoned ROWs, some highway ROWs and some new construction, to near New Haven via Needham, Millis and Douglas in Massachusetts and Putnam, Willimantic and Middletown in Connecticut—in under an hour. (Something along these lines, see notes below.) Improvements on the New Haven Line could probably shorten that run time to under an hour (current speed limits are only 70 mph even on straightaways) and cut the whole travel time to under two hours. On the current, curvy, longer (by 25 miles) NEC, this wouldn't really be possible. Spurs could carry traffic to Providence and Hartford.

From New Haven to New York, land acquisition costs (both monetarily and politically) would be so high that a proper ROW would be difficult if not impossible. However, the current four track ROW, with several major improvements (for instance, replacing all the movable bridges, and bypassing Bridgeport's 30 mph curves with a two-mile-long bridge/viaduct and, yeah, four tracks the whole way), run times from New Haven could be cut significantly.

( * These are based on estimates of 180 mph operation express from Back Bay to New Haven. Acceleration and deceleration were assumed to be 0.8 mph/s. Curve speeds were estimated. Total distance is 128 miles, total time is 54 minutes, average speed is 140 mph.)

Of course, even if you build this segment and utilize the current track from New Haven, you still get to Penn Station in 2:20. Which beats the plane every time.

(I plan to blog about this at some point in the (near?) future.