Archive | RTP Update

Advanced Topics in Congestion

At the last TPAC workshop on the Regional Transportation Plan update, Metro presented their research on roadway conditions (freeways and arterials). There are some very interesting ways to visualize the situation.

[Note: click on any slide to see a larger (and clearer) version.]


A table showing what portion of our freeway and arterial network is congested (at PM peak), by lane mile. A Volume/Capacity ratio of greating than 0.9 is generally considered congested. You get free-flowing traffic up to about 0.8.


The table turned into pie charts.
Note that even though about 25% of the freeway network is congestioned, it’s only 11% or so for arterials. Most of our major road network is working!


This chart shows congestion versus time of day. Regional policy says we should avoid getting congested in the red box (i.e., freeways should be relatively free-flowing outside peak hours, which is important for freight). We’re clipping the edges on I-5 Northbound.


On the other hand I-205 seems to be working pretty well off-peak.


This is a really interesting diagram call a travel time contour. The colors tell you how long it takes to get to the target location (yellow is about 25 min), in this case the Washington Square area. One of the goals for the scenario exercise in the RTP process is to show how these will change with different investment scenarios.


This is for the Clackamas County industrial district.


This diagram looks at congestions not as a question of travel time itself, but rather in terms of variability in travel time (or reliable). Part of the theory is that longer travel times may be acceptable, if they’re predictable.


Travel times past Nybeg Rd. on I-5 seem pretty reliable.


But Highway 26 is a crap shoot!

Selling the RTP

The Trib reported yesterday again on the skepticism from the FHWA on the draft policy chapter for the new Regional Transportation Plan. The Trib attributes the feedback on the RTP to FHWA Oregon Division Administrator David Cox.

The article also included remarked from at least one member of the Oregon Transportation Commission.

Change is hard :-)

Streetcar and the RTP

In the draft policy language for the Regional Transportation Plan update, there is a 3-tier classification of transit service:

  • High Capacity Transit (MAX)
  • Regional Transit (connects regional and town centers)
  • Local Transit (bus)

Streetcar was initially lumped in Regional Transit (along with TriMet’s frequent bus lines). While the proposed Lake Oswego Line might fit that role, I thought it was off-point for most of the ways we’re using and intending to use Streetcar.

So I submitted a comment memo, likely to be discussed as part of a workshop next week. I’d be interested in feedback on it:

To:TPAC Workshop Participants
From:Chris Smith
Date:22 January 2007
Re:High Density Transit

At the last meeting, I made a suggestion that the hierarchy of transit types should include an additional category: Circulator Transit. After further reflection, I think High Density Transit is a better name (it does not make preconceptions about alignment structures). I’d like to expand on this idea a bit to assist our further discussion of the topic.

Purpose of High Density Transit

Provide short-trip mobility in Centers and serve as a place-making tool to foster an urban environment in which system users have easy access to housing, jobs, shopping and entertainment. A virtuous cycle is created in which ridership fuels development which in turn provides more ridership.

The dense urban fabric served and created by High Density Transit provides an environment that offers access to closely spaced land uses by walking and cycling as well as transit. FAR utilization approaches 100% in new development along High Density Transit alignments.

Characteristics of High Density Transit

-Operates in Centers and on Main Streets
-Very High Frequency (sub 15-minutes headways, ideally 10 minutes or less)
-Ease of access (i.e., frequent stops) is more important than speed
-Employs some form of fixed guideway to attract development
-May operate in mixed traffic, does not require dedicated right-of-way
-Has high amenity value

Local Examples of High Density Transit

-Existing Portland Streetcar alignment
-Proposed Streetcar Loop
-MAX between Lloyd District and Goose Hollow

I would be careful to distinguish between Streetcar as a vehicle type and High Density Transit. High Density Transit is about a service profile and the use of a fixed guideway.

While Streetcar serves this purpose admirably due to the capacity, scale and ride experience of the vehicle, Streetcar can also be operated as Regional Transit with greater stop spacing and use of dedicated right-of-way as is proposed in the Portland to Lake Oswego Transit Analysis.

In fact, the Lake Oswego proposal is a hybrid, with Streetcar operating as High Density Transit in Johns Landing and in Lake Oswego, and as regional transit in-between (much as MAX operates as High Capacity Transit outside the Central City and as High Density Transit in the Central City).

How Do We Size and Allocate Freeway Capacity?

Yesterday’s Portland Tribune, in milder terms than the FHWA, editorialized that Metro may be overlooking roads in the Regional Transportation Plan update.

While Steve Clark, the Trib’s publisher, and a mover and shaker on transportation issues in the business community, would probably concede that we can’t build our way out of congestion, the tone of the editorial suggests that he wants us to try a little bit.

Metro’s approach on the other hand is to recognize that freeway capacity is a finite quantity, and we’re better off building better connected local grids to avoid funneling so much traffic onto the constrained freeways.

Another way to look at this is to ask how we’re going to allocate our freeway capacity: with congestion, so whoever is willing to wait the longest gets to use the freeway. Or perhaps more rationally, with some form of pricing, so that the economically most important trips get priority?

This is going to be an interesting discussion to watch unfold.


Update: A few minutes later…

But wait, now the meme is on to

Update: 1/30/07

I don’t know if this is cool or silly, but here’s a case-in-point for the self-referentiality of the blogosphere and the mainstream media. I ran this post yesterday, and was told by Metro staff that it generated a media call from the Oregonian. Today, Jim Mayer runs this story in the O. Then, Gordon Price in Vancouver, B.C., picks up on Jim’s story via the Sightline Institute’s TidePool news service for his blog, Price Tags.

If the spiral keeps going, maybe we can get this story to CNN!

Original Post: 1/29/07

I commented recently that the re-written policy introduction to the Regional Transportation Plan was a strong indicator for really taking a different approach to the role of transportation in acheiving the 2040 vision for our region.

This was confirmed when I had a chance to read the Federal Highway Administration’s comments (PDF, 14K) on the policy draft.

It is difficult to find the transportation focus in this opening chapter of the Regional Transportation Plan. The current focus is about attaining land use goals…

Here, here! Now, if we just started all our land use plans by talking about transportation goals, we might finally acheive integrated planning.