Author Archive | Bob Richardson

News of Other Trams…

Much has been debated about the Portland Aerial Tram project. Yesterday, the City Council, in a close vote, endorsed continuing construction of the tram and committed more city money from various sources to the project.

Interestingly, just hours earlier, passengers on a tram in New York were being evacuated from a stalled system via crane and maintenance carriage. The time from initial failure to rescue completion was about 12 hours, and an investigation into the causes and procedures followed is ongoing.

Regardless of one’s position on the Portland tram, I think the New York system may provide some insights on what to expect in terms of performance and in terms of the potential for failure. I think it is fair to ask PATI what safeguards are incorporated in the Portland design which would prevent, or at least lessen the severity of, a New York style failure.

Here’s a link to a New York Times article on the subject:

– Bob R.

How I would untangle the Rose Quarter

Regular readers will recognize Bob Richardson as “Bob R.” who has provided many cogent and informative comments. I’m happy to now welcome Bob as a Portland Transport contributor! – Chris

The Rose Quarter area is one of the most intense mix of transportation modes in the city of Portland. Three (soon four) MAX lines converge there, Interstate Avenue, Multnomah and Oregon streets intersect with approaches to the Steel Bridge, and there are multiple bus lines using the Rose Quarter as a transit center. Nearby, but not directly intersecting, are freight/passenger rail tracks which cross the Steel Bridge to Union Station.

A complex layout of light rail “interlocks” (track switches) and traffic signals orchestrates the flow of traffic in multiple competing directions.

As some transit advocates (including AORTA) have pointed out, the capacity of these interlocks constrains the potential for growth of the light rail system. With the addition of the MAX Green Line from Clackamas, the area may approach the practical limit for trains per hour of throughput within a decade.

Expanding capacity beyond the current limit presents a conundrum: How do you redo this complex interchange without shutting down the current rail system, which would have drastic short term and medium term impacts on ridership? Furthermore, how can the area be configured to accommodate future proposals such as a new river crossing (bridge or tunnel) or longer trains?

I propose the development of an underground station at the Rose Quarter for the Blue/Red/Green lines in a manner which presents many options for future expansion, eliminates several current conflicts, and provides greater rider convenience.

Full details with pictures on the flip…
First, an acknowledgement and some background…

The images which follow were created using the amazing Google Earth software package. All of the aerial images in this document are copyrighted by Google, but due to subsequent cropping and enhancement some of the images do not include the Google message. Please check out Google Earth, which comes in a free version, for some incredible ways to explore our city (and for that matter, our planet.)

Current Situation

The current Red and Blue Lines meet up with the Yellow Line at rose quarter in a Y-shaped arrangement of track switches known as an Interlock:


A closer look reveals a conflict: In addition to the multiple automobile lanes of Interstate Avenue, Multnomah, and the Steel Bridge ramps, northbound Yellow Line trains must cross the path of opposite-direction Blue Line and Red Line trains. This means that one of those trains must wait before proceeding.


It should also be noted that although light rail is given signal priority, once the traffic signals have allowed automobile traffic to proceed, trains which have “just missed” their opportunity to request priority will have to wait for the automobile signal phase(s) to complete.

The Near Future

With the completion of the Green Line from Clackamas (est. 2009), which will utilize the existing Red/Blue line tracks through this area, there will be a high number of trains per hour operating through this crowded interlock.

Today’s Trains per Hour (peak):

Line Westbound/Southbound Eastbound/Northbound
Blue Line 8 8
Red Line 4 4
Yellow Line 4 4
Totals 16 16 32

2009 Opening-Day Trains per Hour (peak):

Line Westbound/Southbound Eastbound/Northbound
Blue Line 8 8
Red Line 4 4
Yellow Line 4 4
Green Line 4 4
Totals 20 20 40

2025 Trains per Hour (projected peak):

Line Westbound/Southbound Eastbound/Northbound
Blue Line 12 12
Red Line 4 4
Yellow Line 6 6
Green Line 8 8
Totals 30 30 60

Whenever a Northbound Yellow Line train enters the interlock, all Westbound/Southbound trains must wait. In 2025, there will be 6 times per hour when a potential conflict exists due to the Yellow Line. Every 10 minutes there will be an opportunity for a slight schedule hiccup to cause an actual delay.


There will be a Westbound/Southbound train coming every 2.5 minutes, pausing for 30 to 60 seconds at the Rose Quarter platform. If that train is delayed (by missing an opportunity to cross the interchange, or by a passenger holding the door, a pedestrian crossing against the light, or other everyday factors) even by one minute, the next train behind it is now delayed. This sets up a ripple effect. Because the interlock is operating at capacity, trains cannot be expedited through it to remove the ripple. All subsequent peak hour trains could become delayed, and additional factors could amplify that ripple.

Other Problems

The Rose Quarter area has other problems than train interlock scheduling. Passengers wishing to transfer to the Yellow Line must walk over 300 feet and cross three separate, busy signalized crossings. These necessary pedestrian activities further constrain signal phase timing. After large events let out at the Rose Garden Arena or Memorial Coliseum, large crowds of people approach the platforms and jaywalking is an issue.


The current Red/Blue/Green platform area contains a third track used to store an extra train (usually eastbound) to provide immediate crowd relief to events. Any redesign of the transit facilities in this area must accommodate this important design feature.

Numerous groups and individuals have proposed further long-term enhancements to the transit system including a downtown subway, a new river crossing (bridge or tunnel), a Multnomah St. subway, and the modification of the system to accommodate 3-car trains (possible if a downtown subway is constructed.) A redesign should anticipate these plans so that further reconstruction in future decades is not required.

It is also vital that any redesign minimize interruption to the current system. Shutting down the Rose Quarter area for months to rebuild tracks would be highly disruptive to transit usage patterns in the region.

The existing interlock also provides an important connection for Yellow Line trains to travel to and from the maintenance facility in Gresham. This connection must be maintained for normal system operation.


Not directly addressed: New west-side interlock

A problem not addressed by this document: Once the Green Line is constructed, there will be a new interlock at the west end of the Steel Bridge. This interlock will create new constraints on capacity. These constrains can be partially (but only slightly) alleviated by the addition of a third track to the Steel Bridge. Because it is unknown to this author if the Steel Bridge could handle such modifications, that idea has been left out of this proposal.

Grade Separation

Grade Separation means giving a mode of transportation not just it’s own right of way (special lanes and signals, crossing gates) but to construct the route in such a way that conflicts are avoided in the first place (using bridges, ramps, tunnels, etc.)

If the most heavily traveled tracks (the Blue/Red/Green Lines) are grade separated, conflicts with auto traffic, opposite-direction rail traffic, and pedestrian traffic can be completely eliminated. This is the approach this proposal utilizes.

The Proposal

To create an underground “subway” station adjacent to the Rose Garden Arena, positioned under the arena lawn/plaza areas and Multnomah Street:


Purple lines indicate tunnel and station boundaries. Asterisks (*) indicate station entrances with “E” for elevators.

Design Aspects:

  • A large, multi-platform station maintains the current extra-track arrangement
  • The station and platforms are large enough to accommodate 3-car trains.
  • Additional tunnel excavation at the east end allows for a future Multnomah St. subway.
  • Further excavation at the west end allows for a future river crossing (bridge or tunnel) on the North side of the grain elevator facility.


  • Conflicts with pedestrians, cars, and opposite-direction trains are completely eliminated.
  • Various known future growth proposals are accommodated without further need for reconstruction.
  • The station is located much closer to the major use in that area, the Rose Garden Arena.
  • Crowds exiting Rose Quarter area events do not need to cross a street to reach Blue/Red/Green Lines.
  • Transfers to the Yellow Line are now less than 100ft away and require crossing only one street with one direction of traffic.
  • The middle track, in the years before 3-car operation begins, can accommodate (with care) two trains: A one-car Westbound train and a two-car Eastbound train, if desired.
  • During construction, most excavation is away from existing rail lines, requiring minimal disruption to current rail operations.
  • Station excavation can be done with less-expensive “Cut and Cover” methods, using Rose Garden Arena lawn areas as staging areas.
  • Although automobile traffic on NE Multnomah (and the Steel Bridge on-ramp) will need to be closed for a long duration of time, it can be rerouted to nearby streets. Once construction is finished, automobile traffic will move much more smoothly through the area due to 80% fewer trains crossing against autos.
  • Existing surface interlock tracks can remain in place to allow for Yellow Line start-of-day/end-of-day operations and as an emergency backup.
  • Existing Blue/Red/Green platforms can remain for additional storage of up to 3 two-car trains to be deployed in any direction.
  • Design uses almost entirely: Existing public right-of-way, private property containing no structures which can be restored to private use after completion, or private vacant land.

This plan is preliminary… Your comments and questions are appreciated.