[sustran] FW: Bus Lane Capacities (was: Article in GuardianNewspaper)

[Alan Patrick Howes]

This thread is in danger of getting out of control!

For bus lane capacities, the two transit-prof emails quoted below give some very useful background and comment on the Lincoln Tunnel Exclusive Bus Lane (XBL) data found at http://www.panynj.gov/tbt/xblmain.htm - thanks to Colin Leech.

For those looking for arguments for Busway rather than LRT or Metro, look no further than http://www.rppi.org/pu16.pdf . It is written in a North American (mainly low- and medium-density development) context, and rail advocates with blood pressure problems should perhaps avoid reading it. But it does bring together in one place a lot of useful facts and arguments in favour of busways. What it omits is the safety and environmental aspects, which is a pity. More polemic than professional in this respect I am afraid - but I am a stuffy Brit!


-- 
Alan P Howes, Special Transport Advisor, 
     Dubai Municipality Public Transport Department
aphowes at dm.gov.ae
http://www.dubaipublictransport.ae/
Tel:    +971 4 286 1616 ext 214
Mobile: +971 50 5989661


-----Original Message-----
From: Leech, Colin [mailto:Colin.Leech at transpo.ottawa.on.ca]
Sent: Tue, 01 April, 2003 00:57
To: 'Transit-Prof at yahoogroups.com'
Subject: RE: [Transit-Prof] Bus Lane Capacities (was: Article in GuardianNewspaper)


I'm not a member of sustran-discuss, so I cannot post to that list, but feel
free to pass this message along to that list if you wish.

I don't have peak hour figures for the Lincoln Tunnel XBL, but I'm willing
to make a few educated guesses. From everything I've seen including the
material forwarded by Bob Campbell, the lane is pretty much at capacity
today, and bulging at the seams. A normal freeway lane can accommodate
somewhere around 2000 cars/hr. Buses are considered to be the equivalent of
2-3 cars under normal freeway conditions. IIRC the XBL isn't a fully
free-flow freeway (60 mph or 100 km/hr)lane, but has some constraints due to
the spiral approaches to the tunnel, passing through the toll booth area
(although buses don't stop), and the speeds and narrowness of the tunnel
itself (IIRC at one point the Port Authority restricted bus usage to 96"
wide buses, not the 102" wide buses which are pretty much standard today).
So, the guesses of around 600-700 buses/hr that have been mentioned make
sense to me.

It is important to make a distinction between this type of situation
(freeflow highway lane with no stops), and a bus lane in an urban context
with buses stopping to pick up passengers. Here in Ottawa, the downtown
segment of the Transitway operates as bus lanes on Albert and Slater
Streets, with buses stopping every few blocks to board and alight
passengers. We have bus volumes in the 180-200* buses/hr/dir range.
Representatives of other cities have difficulty believing these figures, as
conventional curbside bus lanes generally max out in the 120-140/hr/dir
range. Our geometry is a bit different, and other measures have been taken
to keep the service moving. Nevertheless, we know that we are very close to
capacity under the current operating conditions. The short N-S block lengths
in downtown Ottawa pretty much limit our ability to squeeze out significant
capacity increases via tweaking the traffic signal system further than we
have already done.

* The capacity constraint is during the PM peak, EB on Slater St., when
buses are picking up passengers. We've been around or above 180/hr on this
section for over 15 years. We actually have higher volumes WB in the AM peak
on Albert St. (200/hr range), but the vehicle capacity is higher because the
dwell times at the stops are shorter because most passengers are getting off
the bus.

The capacity of the Transitway would be much higher if it were completely
grade-separated from other traffic, and not constrained by the on-street
operations through downtown. We won't know for sure unless we ever do get
off the streets (unlikely for financial reasons), but the estimates are that
the ultimate capacity of a fully-separated busway with station stops could
be about double the 9-10,000 psgrs/hr that we're currently carrying in the
peak direction at the max load point.

I agree entirely with Alan that most cities (at least, most North American
cities) won't ever have to worry about such capacity constraints. Most of
the new LRT systems built in the last 20 years in North America aren't even
carrying 5000 psgrs/hr in the peak hour, peak direction.

I'll reply to Bob's e-mail with more comments on the XBL.

All opinions are my own
--------------
Colin R. Leech - Transit Planner
Planificateur du transport en commun
OC Transpo - Ottawa, Ontario, Canada
(613) 842-3636 ext./poste 2354
Colin.Leech at Transpo.Ottawa.on.ca

-----Original Message-----
From: Leech, Colin [mailto:Colin.Leech at transpo.ottawa.on.ca]
Sent: Tue, 01 April, 2003 01:09
To: 'Transit-Prof at yahoogroups.com'
Subject: RE: [Transit-Prof] Bus Lane Capacities (was: Article in GuardianNewspaper)


>From the Port Authority web pages:

> WHAT IS THE XBL?
> 
> The XBL (Exclusive Bus Lane) is a dedicated contra-flow bus lane that
> operates weekday mornings between 6:15 a.m. and approximately 
> 10:00 a.m.

My understanding is that it only operates in the AM peak, inbound direction,
as a very long "queue jump" approaching the tunnel. The Manhattan side of
the tunnel connects directly to the Port Authority Bus Terminal, so the
outbound buses don't need a comparable lane in the other direction. The
buses exit directly from the terminal into the tunnel, and outbound traffic
from the tunnel spreads out onto several different highways on the NJ side.
Remember that a tunnel or bridge is almost never a traffic capacity
constraint itself. It is the approaches and merges that are constrained, as
multiple lanes of traffic attempt to merge into a smaller number of lanes.
Of course, the toll booths also slow things down.

> Access to the XBL is limited to buses with a seating capacity of
> sixteen or more passengers. To ensure safety, reduce lane overload and
> maximize mass transportation capacity, access to the XBL is limited to
> regular "for hire" public buses. School buses, vans, taxis, limousines
> and other multiple-occupancy vehicles are prohibited.
> 
> All empty buses are prohibited from entering the XBL during its entire
> period of operation. This restriction allows the maximum 
> utilization of the XBL operation for peak period commuters.
> 
> Non-commuter charter buses are not allowed access to the XBL during
> peak period operating times. Charter Buses are only allowed in the XBL
> after 9:00 a.m., which is past the peak commuter hours.

This all tells me that they are close to the capacity of the lane
(consistent with other information I've heard over the years).

> Buses using the XBL must be equipped with E-ZPass. This 
> requirement has helped facilitate traffic flow.

The buses don't stop at a toll booth. The tolls are collected electronically
from the EZ-Pass as they pass by.

> The XBL keeps some 10,000 cars off the road each day, easing 
> congestion and improving air quality.

This seems low, considering the figures given earlier of 60,000 commuters. I
think somebody goofed on the proofreading. 

> A strong economy and increased overall traffic are contributing factors
> to XBL congestion. From 1996 to 1998, we experienced a 4.9% 
> increase in bus activity at the Lincoln Tunnel.

Plus added demands after Sept. 11, 2001 (along with PATH and the NJT/Amtrak
rail lines into Manhattan). There were some serious capacity problems for
public transit crossing the Hudson River even before Sept. 11, which were
made much more critical following the loss of the PATH line to Lower
Manhattan.

All opinions are my own
--------------
Colin R. Leech - Transit Planner
Planificateur du transport en commun
OC Transpo - Ottawa, Ontario, Canada
(613) 842-3636 ext./poste 2354
Colin.Leech at Transpo.Ottawa.on.ca