Monday, December 13, 2010

The Helix and the XBL

My post last Wednesday on Chris Christie's plans to use the Port Authority's $3 billion ARC tunnel contribution on a bus garage, reconstructing the Lincoln Tunnel helix, and replacing the cables on the George Washington Bridge got some interesting comments, both here and when Angie Schmitt featured it on the Streetsblog Network. Some of the comments pointed out that since buses use roads, this doesn't have to be all for cars. Sean, Kate and Alon on Streetsblog, and Busplanner here, all argued that the helix reconstruction could help speed buses.

For those of you just tuning in, the Lincoln Tunnel exclusive bus lane is a counterflow lane. One of the lanes that is normally reserved for outbound traffic is allocated for inbound buses during the weekday morning rush, but then it's over, and there is no outbound XBL. It carries thousands of people every morning, in an impressive feat of bus service, and is quite likely possible for the continued viability of most of the country's private bus lines. Several transit advocates have argued for making the XBL two-way round-the-clock, and for doubling it in the morning rush. The Port Authority has studied this, but there hasn't been much movement on it. One of the items in the Strategic Plan was $800 million to expand the XBL, but the helix reconstruction and the GWB cables seem to have jumped ahead of this.

I agree that since the Lincoln Tunnel exclusive bus lane goes on the helix, it would be negatively impacted if the helix were to fall down. But rebuilding the helix by itself would not actually increase capacity. The current helix is three lanes inbound and four outbound, and we could conceivably press to increase that to four inbound and five outbound, with one in each direction reserved for buses.

The problem is that the helix still connects to a six-lane road cut through the bedrock of the Palisades, and we can't add any lanes to that without some serious blasting. Increasing the capacity of the helix would just move the backups a mile further out of the city, to the point where the lanes merge down to three in each direction again. This is the reason why most of the serious plans to increase the XBL capacity involve taking another car lane.

However, we've got some pretty clear indications that Christie understands that this is about subsidies for drivers versus subsidies for transit, and we know where he comes down on that issue. I wouldn't expect him to say, "Okay guys, sure, let's take a general traffic lane and give it to bus riders!" Unless it's some vicious sarcasm like his mom dished out with her bit about the money tree.

That's not to say that savvy politicians couldn't get an expansion of the XBL folded into the helix reconstruction. Maybe if everyone plays their cards right, Cuomo could threaten to block the helix reconstruction as a car project unless XBL expansion is included in it. But that's not going to happen if everyone says, "Well, the helix benefits buses too!"


Jonathan said...

Thank you for the informative post. I would just like to use this space to point out that the key to the XBL is that the Lincoln Tunnel is the world's only three-tube tunnel, with six lanes of traffic total going under the river. The Holland, the Queens-Midtown Tunnel, and the Brooklyn-Battery Tunnel are only two-tube tunnels.

Kudos to the Port Authority for thinking ahead.

Cap'n Transit said...

No other three-tube tunnel? Well you learn something new every day. Thanks, Jonathan!

...of course that doesn't mean we couldn't put a bus lane in the Brooklyn-Battery Tunnel or the Holland Tunnel. It just makes it a bit more difficult politically.

jazumah said...

The helix takes a pounding and the geometry on it is very tight. The point of good road maintenance is to fix things before they fail. I think that the XBL can take a second lane as long as they allow charter buses in it AND they upgrade JFK Boulevard to take the overflow traffic. This is a project that can benefit everyone.

Rail construction costs are out of whack in this region. It is going to be buses that bring the next phase of relief until the MTA turns its Capital Construction department into an actual construction company and hires its own workers.

Alon Levy said...

I don't think I said that the helix was good because of the buses. I said that good use of the money would be making the XBL all-day, in both directions.

All transportation construction costs are out of whack in the US, not just rail construction costs. Look at the Tappan Zee Bridge, for example.

jazumah said...

There is no need for an all day XBL. AM Peak (two lanes to NY) and PM Peak (one in each direction) are enough. The lack of priority in the PM peak to Manhattan destroys bus schedules and increases costs.

Cap'n Transit said...

No need for an all day XBL, Joel? Maybe, but there's certainly a need for one on weekends. I've sat in traffic on that ramp from the Turnpike many Sunday evenings.

The main value to an all-day XBL is predictability. They're always available for buses, 24/7. You don't need to move miles of barriers, just in the merge zones at either end.