Beltline streetcar grass track adds incremental cost
Streetcars on turf tracks in Nordhausen, Germany. Photo: Vincent Eisfeld via Wikimedia.
Putting lipstick on a pig can cost a pretty penny. But it won’t break the bank.
That’s our takeaway from a June report by a MARTA consultant on a proposal to use a grass track bed for the Beltline streetcar. The report indicates – not in so many words – that embedding the track in grass might add 1 percent, possibly less, to the overall project costs.
Atlanta Beltline Inc. and other streetcar boosters have been pressing MARTA to switch the Beltline rail track system from more conventional concrete and gravel beds to a turf, or “green,” bed. Aside from looking nicer and perhaps dampening the sound of the streetcar, vegetation can slow stormwater runoff and reduce temperatures in very close proximity to the tracks themselves.
Of course, not building the streetcar would be much better for the environment. The benefits of grass tracks are a tiny fraction of the cooling, drainage, air-cleansing, aesthetic and climate benefits that would be lost by clearcutting trees and bulldozing meadows to make room for the tracks, trains and overhead wires.
HDR Inc., the design and engineering contractor for the Streetcar Extension East, was tasked by MARTA to evaluate turf tracks for the 1.3-mile segment of that project that would form the first stub of the Beltline rail.
“An Embedded Track with Vegetation at top-of-rail (TOR) is recommended because of its superior durability, ability to preserve the Atlanta BeltLine's existing viewsheds, and similar rail testing protocols with the existing streetcar track,” the report concludes.
The recommended system would use in Bermuda or Zoysia grass, and would require irrigation lines, frequent mowing and additional maintenance. While such a system would be more expensive than any of the other systems considered, its maintenance costs would be lower than other turf approaches.
Detail on grass track system recommended by HDR. Image: HDR.
HDR places the cost of “embedded track with vegetation at top-of-rail” $880 per linear foot, which equates to about $6 million for the 1.3-mile Beltline portion of the Streetcar Extension. Extended to the entire 22-mile rail loop, the cost would be on the order of $100 million.
Current design calls for a mix of embedded concrete ($795 per foot) and retained ballast ($640). To come up with a ballpark figure, we settled on a midrange number for the existing design at $700 per foot. Then, we multiplied $700 by the number of linear feet and subtracted the total from the estimate for the turf system.
Under that scenario, the 1.3-mile Streetcar Extension stub would increase in cost by about $1.2 million. Extended for 22 miles the increase would be $20.9 million. Big caveat: These are back-of-the-envelope numbers only intended to give us an idea of the relative scale of replacing the current design with turf tracks.
So what is that scale? The Streetcar Extension East currently is projected to cost $230 million, with only about half of that on the Beltline portion. We estimate that the full 22-mile loop would run $2.5 billion. So it seems that grass tracks is likely increase the streetcar’s cost in the neighborhood of 1 percent, possibly less.
The report didn’t detail the increased maintenance costs that would accompany the switch. Operating subsidies for the streetcar are expected to be high. According to MARTA’s most recent report to the National Transit Database, the existing Atlanta Streetcar costs $48.60 for each mile by a single passenger to operate.
Advocates have been pushing for two other significant changes in the streetcar’s design, both of which are likely to be more difficult to make. MARTA officials have told us that fencing or barriers to prevent pedestrians from wandering onto the tracks remain in the design because of liability concerns about a streetcar next to a busy multi-use path.
The other change — eliminating unsightly overhead electric wires — would be the most difficult of all. MARTA have to replace the Atlanta Streetcar’s existing fleet with battery-powered cars and would have to change make other changes to the complete line. But the real deal killer, according to our sources, is that streetcars powered by batteries present a fire risk, so MARTA would no longer be allowed to use the streetcar's maintenance and repair shed under the Downtown Connector. Alternative locations along the route for maintenance and repair are difficult to find and would be prohibitively expensive.
— Ken Edelstein
