Monday, May 05, 2008

Trains and traffic

While I was in Dallas recently for a cousin's wedding, I came across this cover story in the Dallas Observer (their version of the Houston Press) about downtown traffic snarls caused by DART's too-frequent light-rail trains and the blockages they create. Evidently, DART promised - in writing - a subway conversion when it became necessary, but now seems to be having trouble meeting that obligation.

This debate has not really been on the radar at all in Houston, even though new lines will create new north-south crossings in addition to the existing east-west ones for the Main St line. I'd like to think that Metro, the City, and the downtown boosters are on top of this and have it all worked out, but I don't know. If you have some insight, comments are appreciated (Christof, this means you in particular ;-).

On to the story excerpts:
The real story is that DART could be on the verge of severely shafting downtown Dallas for the next decade. I mean the big shaft. The do-or-die shaft for downtown.

DART must build a second rail line through downtown, some of it in a subway, or downtown is screwed. Unpleasantly, aberrantly so.
Unless DART moves quickly to build the second downtown line, the existing downtown line is going to become a solid wall of trains down Pacific Avenue from the east end of downtown to the west end, with car and bus traffic stacked up at the crossings like cordwood.

That second line downtown is the big story. It has been for nearly 20 years. In 1990 after years of debate, the Dallas City Council forced DART to sign a contract promising to build a second line downtown with a subway when train traffic on Pacific Avenue reaches a certain point.
Now imagine putting a solid wall of trains down Pacific and Bryan streets. Then the only way you can drive from City Hall to McKinney Avenue is by going all the way out of downtown, either west to Industrial Boulevard or east somewhere in deepest East Dallas, because the stupid trains have got you totally blocked off.

What do you do? I know what I'd do. I'd say screw downtown. I've got enough aggravation. If I am a major employer, I don't think I'm going to rent three floors of a high-rise if it's going to take me and my employees an hour to get out of downtown.
According to DART's own published traffic projections, peak capacity for the Pacific Avenue "transit mall" is 24 train trips per hour. DART figures that if 24 trains an hour pass up and down Pacific, that will leave two and a half minutes between them, which should be enough for the cars and buses to barely squeeze through.

(side note: I believe the Main St line is currently running at six minute headways)

Any more trains than that, and the cars and buses are dead in the water. All day long, crossing Pacific will be like trying to cross an eight-lane boulevard at rush hour without a light.

The solution? Don't put all those new trains to the suburbs down Pacific. Build a "second alignment" through downtown with a subway. Why a subway? Well, otherwise the second alignment will still have a tendency to screw up traffic, even if you put it 10 blocks from the first one. It's like two long lines of hurdles 10 blocks apart.

In fact, it could be even worse. You could get caught between the two, so you wouldn't even have the option of turning round and giving up. Then your only option would be to climb up on the roof of your car and hurl imprecations at the Fates. That would be a memorable way to spend your last visit to downtown Dallas. Ever.

The 'burbs will never admit this, but I have been talking to DART board members on both sides, off the record, for months: The truth is the 'burbs don't care if downtown traffic gets backed up. They want their lines. No matter what. If traffic downtown gets messy, too bad. Downtown Dallas is for the City of Dallas to figure out. The 'burbanites are just passin' through anyway.
I won't dredge too deeply through the rest of the DART budget, but it also assumes major new borrowing levels based on two types of costly loans the agency has never taken out before. And it assumes the Texas Legislature will change the law to let DART borrow money without voter approval. (similar rumblings from Metro?)

Listen. If I had to bet right this minute whether they will come up with the money for the second downtown alignment, or they won't—I would put my chips on won't. And they'll tell us they are very, very sorry about it.

In addition, let's hope Metro isn't heading down this same path, despite recent turmoil indicating it might:
On November 22, DART CEO Gary Thomas reveals to the DART board that DART has under-estimated its capital construction costs by, uh, let's see...100 percent. Instead of costing $1 billion, DART's current expansion plans will cost $2 billion, Thomas says.

Thomas explains he has kept the shortfall a secret from his board for a year, because he was hoping it would go away. I submit this is like a guy with a large tusk growing from his forehead. You say, "Gary, pardon me, but you have a tusk on your head." He puts his fingers to his lips and says, "Shhh."

The DART bureaucracy and the suburban members, meanwhile, have come to a peace agreement on Thomas' billion-dollar boo-boo. There will be no formal external audit of DART. A few underlings have been fired. Thomas will keep his job. It's all forgiven and forgotten.

So far, DART is making Metro look pretty good by comparison. Let's hope it stays that way...

Update: Christof responds with his very good analysis (as always).

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At 5:25 PM, May 05, 2008, Anonymous Anonymous said...

It's funny how the arguing factions in DART's drama is the suburbanites wanting light rail and not caring about downtown citizens. And here in Houston the suburbanites complain their taxes are going to only give the inner city a little train to ride.

This does raise a good question. East-West lines in downtown running at grade will bring downtown to screeching halt when they run at peak times where headways are short.

Having the current north-south line isn't that bad since the largest traffic pattern for rush hour is north-south also. This traffic pattern easily gets you on I-10, US 59, and SH 288. It just leave I-45 access partially hindered, but not greatly.

METRO better consider underground or overhead configurations. And i think i can get many to agree against overhead. I've looked at the evolving plan sets for the University line (Kirby to Hilcroft segment). The The elevated portions through Greenway Plaza along Cummins will not be fun for the new apartment complex built there and the Koch Building office tenants.

The bridge will also likely lead to the relocation of Princes Hamburgers and other business in that strip center.

The latest posting on Christof's blog at CTC is showing two east-west lines for each direction of track. this to me means at grade.....

Underground would mean it could go under any street.

At 1:44 PM, May 06, 2008, Anonymous Anonymous said...

Building a subway, even a short one, is horrendously expensive. If surface light rail is in the range of $50-100 million per mile, you can probably add a few hundred million per mile for a tunnel in a densely-built downtown with lots of underground utilities. I'm guessing a minimum of $500 million per mile for a subway.

The cost is almost surely the main issue. DART has seen explosive growth in the cost of its plans (surface tracks to the suburbs), and it is struggling to just to build the track it has promised. A downtown tunnel? It's just not an option in the current transportation funding environment.

At 1:59 PM, May 06, 2008, Anonymous Anonymous said...

Yes, but that seems to be the only option to make an east-west line in downtown palatable.

I can't imaging how traffic on San Jacinto or Fannin would back up during rush hour with the short headways.

Imagine getting out of a ball game (baseball or basketball) would be night to have to cross a surface light line that I would assume be busy to handle some of the patrons of the games too.

I would argue building light rail in any funding environment is not necessary the best thing to do with transportation funding that is always limited.

At 2:20 PM, May 06, 2008, Blogger ian said...

"I can't imaging how traffic on San Jacinto or Fannin would back up during rush hour with the short headways."

The Southeast and Harrisburg lines running east/west through downtown will not operate with signal preemption like the Red Line, so north/south traffic shouldn't be effected much, regardless of the headways.

At 2:39 PM, May 06, 2008, Anonymous Anonymous said...

ian said...
The Southeast and Harrisburg lines running east/west through downtown will not operate with signal preemption like the Red Line, so north/south traffic shouldn't be effected much, regardless of the headways.,
There has to be some signal modifications for this to work properly. The Southeast/Harrisburg lines will BLOCK north/south traffic and also affect the newly sync'd signals.

At 2:59 PM, May 06, 2008, Anonymous Anonymous said...

Good point Anonymous,

North-South signals are working pretty good right now. I could fly through downtown and midtown even during rush hour. East-West is a different story since Main street screws it up.

So what would happen when the new east-west lines cause the lights to go out of sync?

I do know that these traffic system can re-sync themselves. It's not difficult and it is automatic, but it'll have to do it after ever time a train messes up the syncing. I used to program these things while interning in college at the LaDOTD.

At 3:10 PM, May 06, 2008, Anonymous Anonymous said...

Trains do not have to have the right of way. I know right now that all lanes get a red light as a train passes through. We can make trains wait you know. Just because we dont do it today, doesnt mean we cant tomorrow.

Hopefully someday, people will get used to living with trains, and we can manage our traffic better instead of having everyone stop for the train.

At 4:22 PM, May 06, 2008, Anonymous Anonymous said...

I know the streetcars in New Orleans follow all traffic signals with cross streets. If light rail is supposed to be much better than buses, then the ability to move through without having to wait at red lights make them much better and efficient.

The city and METRO will have to decide on which mode is more critical in this issue. Having the train stop at red lights means the automobile is more important than the train (which I have no problem with, worked in New Orleans for the last 100-yrs).

Imagine if signature buses could have the power on traffic signals like police and fire trucks. Outside of the few stops, the bus would be able to barrel through all signals. Not much different than light rail now.

It may event take out a pedestrian and bike rider or two....

At 10:09 PM, May 06, 2008, Anonymous Anonymous said...


Having the train stop at red lights means the automobile is more important than the train (which I have no problem with, worked in New Orleans for the last 100-yrs).

Agreed. Obviously, having trains stop for cars slows them down substantially. However, the biggest slow-down is never the trip itself -- it's waiting for the train to arrive.

If you can set up reliable schedules and space transit vehicles less than 10 minutes apart at virtually any time of day (perhaps more frequent at rush hour) then the mode of transit will be convenient regardless of whether it has to stop and wait at intersections. And in any case, we need to keep rail from holding up traffic. Most people still travel by car; roads still should have priority.

At 8:13 AM, May 07, 2008, Anonymous Anonymous said...


Christof has some new information for us. The East-West trains in downtown will essentially act like cars. They will stop at all red lights and will wait behind other cars in the lane.

At 11:43 AM, May 07, 2008, Anonymous Anonymous said...

I've always argued with people here in Houston that if they ever went to London, they would want some sort of Train/subway in a heartbeat.

Obviously, the London Tube wasn't built overnight, so, we currently have one line and progress for better mass transit is going to take a long time.

But, one thing that I've always noticed about London is that the Tube can take you almost anywhere in the central area, but, as you move out, the stations are spaced further apart. So, what they do is to but local buses that run in circles around the Tube station. Therefore, once you arrive at the tube station, you get on your local bus which puts you within blocks of your destination (office/home/shopping/eating...)

To me, that is what we are not getting here. We have good park and rides that take people from out of town into town and back, but, if you are not "on the route" you are pretty much screwed.

I hope that as the next lines get built, there will be additional local bus service around them so that we won't have to walk so far in these long, hot Houston summers.

At 11:58 AM, May 07, 2008, Anonymous Anonymous said...

We had that. Downtown had trolley buses that if METRO didn't cancel the service would do exactly what you want. The medical center also has a similar concept that is still ongoing.

The Uptown District also had this separate from METRO as a free service that ran primarily through the middle of the day.

Outside of those area, Houston doesn't have the population to support much more. Rail is already financially unfeasible in most measures, luckily what will be spent on it in this city will come slowly.

At 12:02 PM, May 07, 2008, Anonymous Anonymous said...


Thinking in a perfectly selfish way, I live in the Western Suburbs, but, also work in the not so far Western Suburbs (Energy Corridor).

I think that out here, there are enough businesses that have commuters coming from the west side that could then get on vans that do the circles.

I understand that it is only one instance, but, imagine that there are other such scenarios around

At 12:51 PM, May 07, 2008, Anonymous Anonymous said...

Well, don't look to our METRO.

The figured downtown didn't have enough to keep their cirulators going.

I would think Westchase would be another good area too.

At 6:18 AM, May 09, 2008, Blogger engineering said...

thanks for the observer article.

to add to the discussion. when i worked in dallas on the light rail segment that goes to garland i remember it took just about the same amount of time to walk along pacific avenue as taking the light rail. the segment where the light rail went 30 mph or more was where it is underground. but this is related to the number of stops and distance between them. similar speeds could be obtained on surface streets but there are challenges related to them.

my experience in the london tube is similar. it is often quicker to walk between two or three tube station following the surface streets than it is to take the tube. it takes some time to access the station from the street and then have to wait for the train.

during peak hours the london tube can be horribly, tons of people and trains are packed. similar issue in moscow and kiev. but super packed subway systems in the old soviet union are much better than walking outside in sub zero weather (also i think the distances between stations are much longer).

how these related to houston?

personally, i would think if light rail does not have preference at street intersections then a bus system would be more efficient and a lot cheaper. the focus should be about providing better and more efficient transit service at less cost.


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