Metro discusses hot cars issue

As summer heated up this year, many riders rediscovered an old frustration: Metro cars with malfunctioning air conditioning. On sweltering days, these cars can be even hotter than the outside.

After seeing so much angst online from one of Metro’s most frustrated customers, @fixwmata on twitter, I asked Metro spokesperson Dan Stessel for some help with the hot car situation.

In order to understand why WMATA has so much trouble with their railcar air conditioning units, it might be helpful to discuss how they work.

Like most household and commercial air conditioning, Metro uses a technology called vapor compression, which has been in use for over a hundred years. It works by pumping a refrigerant to a high pressure and temperature. Then, in a heat exchanger called a condenser, air pushed by a fan removes heat from the hot refrigerant, causing the hot gaseous refrigerant to condense and become a liquid.

This high-pressure liquid is forced through a pressure reducing valve, making it cold. The cold fluid is sent through another heat exchanger called an evaporator where heat from the air is transferred to the cold refrigerant, causing it to boil. The air becomes cold and is sent to the space to be cooled, and the refrigerant warms up, boils and becomes a gas again. The cycle repeats when the gas is pumped to a high pressure again.

Metro uses two different refrigerants. The agency uses R-22 for the older cars and R-407C for the 5000 and 6000 series cars. Each car has two air conditioning loops, one for the front and one for the rear.  An evaporator and fan are at each end of the car, and two compressor-condenser assemblies are located in the middle of the car. Each air conditioner provides up to 8 tons of cooling, or about 2–3 times the amount that a typical house might have.

A number of things could go wrong and cause the air conditioner cycle to stop.  Electrical controllers for the pump or fans could overheat and cause their circuit breakers to open, protecting the system from fire, but also turning off the flow of refrigerant or cold air.  The refrigerant loop could spring a leak, and the pump would shut down because there is too little refrigerant to move around.  Since the condenser is located under the rail car, the heat exchangers can get clogged with leaves and debris, and which means the pressure downstream of the pump would become too high for the pump to work against.  Also, the pump could break or sieze up.

Metro checks the air conditioning system’s health during the daily safety test. They do not put cars out for passenger service with non-functioning AC, but sometimes a car is put out when the AC system is not operating at 100% of its rated capacity. Metro depends on these daily safety tests or employee reports to find cars that are not working properly.

Metro said that having customers report hot cars helps bring road mechanics to the scene. Sometimes the fix is as easy as resetting a circuit breaker, but more often it requires isolating the car and then removing it from service at the end of the line so it can be repaired.

Metro’s AC failure increases dramatically when it is hotter than 93 degrees out. For example, there were 9 total failures on July 27 with a peak of 93 degrees, but on July 29 there were 63 failures with a peak of 104 degrees. Some of the equipment would be capable of cooling a car with the lower heat load, but extreme temperatures cause more failures and lower performance. Having cars wait outdoors at the end of the line with the doors open is particularly bad for the system.

The hot cars reported after August 1 on were reviewed, and all of them have been identified as needing some corrective action.  Six of those cars are still out of service for AC repairs.  Sometimes, there are repeat failures, with 50 repeat failures out of 1104 cars.

Metro said that they found a fix for the 5000 series cars and have begun buying materials to fix the issue.  A software improvement will also help the 5000 series AC systems once they are refurbished.

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I’ll be on the radio tomorrow with Donald Shoup and DDOT

The Kojo Nnamdi show on WAMU 88.5 FM will be hosting a discussion about variable-rate “performance” parking in the District, featuring Dr. Donald Shoup of UCLA, author of “The High Cost of Free Parking”, and Karina Ricks, Associate Director for the Policy, Planning and Sustainability Administration in the District Department of Transportation. I’ll be on the show as well. We will be discussing the two performance parking pilot districts near the ballpark and Columbia Heights, the new performance parking pilot in San Francisco, SFPark, and other parking management improvements in DC and around the world. Please join us at noon for an interesting discussion.

Listen live and call in with your questions to 800-433-8850 or tweet your questions to @kojoshow.

Here’s the article describing the show (from

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San Francisco begins performance parking adjustments

San Francisco will soon start adjusting parking meter and off street garage parking prices based on measured demand. On Monday, the city described the method they will use to make the adjustments.

On-street metered blocks will have prices vary by time of day, in three or four time periods. While some meters open earlier in the morning or run later at night, the changes between morning, afternoon, early evening and late evening time periods will be kept consistent for customer convenience. Some blocks serve a mid-day office crowd, others daytime tourists and shoppers parking later in the day, and others late night entertainment.

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Welcome to This is your first post. Edit or delete it and start blogging!

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>Metro service guarantee


Yesterday, Metro had serious blue and orange line problems in the morning. A power cable downtown failed, requiring an emergency repair and single-tracking, which delayed many riders for over an hour.

Some transit systems in the US have a service guarantee policy, where if your trip takes much longer than scheduled, you can either obtain a refund or a credit for a future trip.

Metro staff investigated these other policies, and presented their findings to the Board last year.

Philadelphia (SEPTA) is the most generous, giving customers a free future ride if you are more than 50 minutes late. Boston (MBTA) provides free service if you’re delayed more than half an hour. New York provides free service if the delays are more than an hour.

Metro’s policy is not that helpful. Metro will refund the boarding fare if you enter the same station you left “during service delays”. Ths service guarantee doesn’t let customers go to their final destination and is vague about when it applies. I haven’t been able to find a service delay where Metro officially applied the policy, usually it is announced by the Station Manager at stations where overcrowding is becoming a problem.

Metro should change their policy to something more like MBTA. A half-hour delay for a trip that typically takes an hour or less is a serious disruption of service. Customers may not know they’re going to be delayed or the extent of the delay until they’re part of the way there. The service guarantee should not require customers to return to their starting point in order to get a refund.

The service guarantee should work like this: Customers with a registered SmarTrip card should go online and find the informaiton about the trip that was delayed. The customer should then send in the trip information (origin, destination, date and times, SmarTrip card ID). After a verification that there were actually unscheduled service delays during that time, the customer’s SmarTrip card should be refunded the fare for that trip. Refunds would not be provided for scheduled service delays when they are announced in advance, or acts of God.

Metro is already under scrutiny for shortchanging safe operation of the system in order to maintain scheduled service. But the sort of problems that cause major delays are more often the kind of problems that come up unexpectedly and are the result of degrading system conditions, such as track fires, switch malfunctions, or railcar maintenance problems. A fare guarantee would put pressure on the system to fix these items so that they don’t break down during operation. Since the guarantee does not affect scheduled service disruptions, it would not pressure Metro to avoid doing critical maintenance on the system.

Metro’s peers in the transit industry offer customers a refund or credit when service is delayed. Metro should too.

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>DDOT proposes Barracks Row lot price cut, other performance parking changes


DDOT has measured occupancy for the Ballpark and Columbia Heights performance parking districts, and is making some changes to meter prices. Some crowded areas are getting parking meter price increases, and some crowded areas are being left the same. DDOT improved their report by following advice we proposed in the last review, and is spending the parking meter revenue on valuable local improvements.

DDOT found that the parking lot underneath the Southeast Freeway on 8th Street SE in Barracks Row only collects about a dollar a day per space, and proposes reducing the price to $0.75 per hour. This is an appropriate change, and should allow people parking in the area a cheaper option than parking on the main commercial street. DDOT should also consider increasing the time limit for this lot to four hours until 5pm and unlimited after 5pm to encourage people with longer anticipated stays to use it, thus leaving the more convenient spaces for people with shorter term needs.

Although many areas in the performance parking zone had measured occupancy above 100% (made possible because of illegal parking and smaller than average cars), DDOT does not propose increasing the meter rates in many areas where the occupancy is high. For some blocks near the ballpark, DDOT proposes increasing the rate, between M, South Capitol, and 2nd streets and the Southeast Freeway. The area the agency chose has maximum occupancy only at 86% during Nationals ball games. The report states that the area has only 56% maximum occupancy, but DDOT explained to me that was the figure for all blocks, including resident permit parking. To improve understanding of their recommendation, DDOT should list in a separate table the metered blocks and their occupancy, and whether they have been included in the proposed price increase.  After looking at the specific blocks chose, I can see why DDOT selected those meters. This is a big improvement from the last performance parking report for this zone published in 2009, where DDOT recommended raising prices for blocks having high occupancy, but specific blocks were not identified and the prices were not adjusted.

For some areas with very high parking occupancy such as 8th street and Pennsylvania Avenues SE, DDOT told me that they wanted to avoid adverse impact on District businesses during the economic downturn and had attempted to use other means such as time limits to manage occupancy rather than adjusting price. It appears that using time limits is not having the desired effect, because the blocks are all showing excessively high occupancy, and my visits to the area during the busiest times have confirmed that parking is very scarce in the area. DDOT is working on building community support for performance parking so that price adjustments can be implemented.

The local stakeholders are concerned about the effects performance parking is having on local resident permit parking blocks. DDOT pointed out the importance of being sensitive to the local community’s opinions, and I understand that, but I’ll also note that right now the visitors looking for parking on residential blocks are those that don’t want to pay for parking combined with those that are willing to pay but cannot find a metered space. If DDOT increases the prices on crowded blocks, at the very least the people willing to pay can find a space, and the extra money collected can help fund enforcement on local resident blocks. Once pay by cell is implemented more fully in the city, the closest resident permit blocks could be changed to resident permit blocks with visitors also paying by cell or walking to the main street to obtain a pay and display receipt.

In the Columbia Heights performance parking zone, DDOT found that all the multispace meter blocks had occupancy rates above 85%, which should lead to higher meter prices in the zone. DDOT proposes extending the meter hours in the zone to 10pm, and increasing the prices on some blocks to $2.50 for the first hour, and $3.00 for each subsequent hour, with a two hour limit before 6:30pm and three hour limit after 6:30pm.  This would be the highest street parking rate in DC. In the last performance parking report for this zone, DDOT recommended increasing the parking meter rates and hours, but the recommendation lacked specifics and stated that the adjustment would happen only after the streetscape project was complete. The current report says the adjustments should happen in April 2011. For the Columbia Heights performance parking zone, DDOT should be commended for implementing the task of adjusting rates according to occupancy.

Occupancy for each block is reported as a number of spaces, number of cars parked on average and the maximum number of cars.  This is a big improvement which was recommended in the article we wrote on the last performance parking report. However, to the extent that DDOT can communicate more information about parking, the occupancy should be reported as an average and a 90th percentile occupancy, which eliminates that problem that reporting a maximum might cause if the maximum is an extreme outlier.

Part of the reports list the revenues collected from meters and the local non-transportation projects DDOT is funding from meter revenues. DDOT has collected almost a million dollars from parking meters in the ballpark performance parking district so far. Of this, over $800,000 has been spent or dedicated for local non-automobile transportation improvements. These projects include BigBelly Solar waste collection systems, benches, historic district signs, and bike racks in 2010. In 2011, with revenue generated by performance parking, DDOT plans to install three or four Capital Bikeshare stations, install an information kiosk at the Eastern Market metro plaza, and perform a transportation study for the Capitol Riverfront district, which will include a study of the M Street corridor for streetcars. These are great projects, though I think the performance parking concept might be more attractive to area businesses if the money could be spent on a wider range of things like sidewalk cleaning, snow removal and graffiti cleanup.

In the Columbia Heights area, DDOT has collected $52,000 from meters and is going to dedicate funding to traffic calming sidewalk bulb-outs, replacing concrete and brick sidewalk surfaces, and upgrading foundation walls. DDOT has also provided funding to streetscape projects for Park Road and the Farmer’s Market.

Based on high occupancy, DDOT plans on expanding multispace meter installation to the waterfront area on Water Street and Maine Avenue. DDOT will also look into adjusting the rates based on curbside occupancy as it does elsewhere in the zone.

DDOT is getting closer to performing all the actions required by the performance parking legislation. They’re measuring occupancy, reporting the data, recommending rate changes, and spending the money locally. However, in many areas with high demand, prices are not increasing as they should.

Compared to the previous performance parking reports, I would say this report is a big improvement. Reporting the data on a block-by-block basis is tedious but important. The money is being spent on local improvements which help the pedestrian and cycling environment, and everybody becomes a pedestrian once they’ve parked. Unlike the previous report, which called for vague increases in prices, this report specifies what blocks will have changes and what the prices will be.

It should be noted that DDOT is running one of the only parking systems in the US where the occupancy is measured and reported, and the prices are actually being adjusted. The other such program is in San Francisco, and that program is supported by a fairly substantial federal grant.

Recommendations for the next report: Reinstate the table showing the revenue collected and how it is being spent. Separate out the occupancy table between blocks that have multispace meters and those that have other parking controls. Make a recommendation concerning the price for every multispace meter block. Obtain community buy-in to follow the variable price policy on very crowded commercial streets like 8th Street and Pennsylvania Avenue.

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>New Blog

>Hello, loyal readers. I’ve started a new blog project that’s focused on advocating for unlimited monthly transit passes in the Washington, DC area. The concept is that riders should be able to pick a dollar amount, pay 40 times that amount and get a transit pass good for unlimited trips of equal or lesser value for a month.

Please check it out at

Also, you can follow the Twitter account @smartpasses or become a fan on
Thanks for reading!
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>Two years later, Metro trains keep failing in service


In September 2008, I concluded that Metro’s reliability was terrible. Using their reported breakdowns and delays in May 2008, Metro appeared less reliable than even the worst line in New York City, breaking down about twice as much.

Taking new data from May 2010, Metro’s reliability appears to have deteriorated even more, with twice as many trains being taken out of service for mechanical problems, 30% more trains being removed from service for door problems, and more than three times as many trains that cannot be placed in service due to management failures such as not having railcars or operators available.

On the bright side, there were fewer trains delayed without being taken out of service.

Here’s the coded data and the spreadsheet. The analysis method is described here.

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>Metro signed Google agreement in July


Google and Metro signed an agreement on July 22, 2010, to provide the Google Transit service, according to documents obtained via public information request.

Metro had previously stated that Google Transit was expected to go live in mid-January 2011, more than two years after Greater Greater Washington started a petition campaign to encourage Metro to allow Google to display transit routing and schedule information.

The agreement appears to be based on the typical Google boilerplate agreement

Metro was not able to get Google to pay for the use of the data, one of Metro’s early sticking points

The indemnification paragraph from the boilerplate agreement appears to be missing, which means that Metro would not be held liable for any mistakes caused by Google and did not agree to legally defend Google if they were sued.  This was one of Metro’s biggest objections to signing the boilerplate agreement.  We first reported that Chicago was able to remove this indemnification from their agreement.

Either party may terminate the Metro agreement, unlike the boilerplate agreement, which only gives that option to Google.  The Metro agreement provides rights to both Metro and Google where the boilerplate agreement only provides them to Google.

The agreement Metro got looks like the best they could hope for.  It’s balanced and removed the features Metro found most objectionable.  Metro’s status as one of the largest transit agencies in the country allowed them to negotiate from a better position than most agencies.

I haven’t been able to get an update on the actual Google Transit release date.

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>Why basic engineering knowledge is important


From Gizmag:

“We have mile after mile of asphalt pavement around the country, and in the summer it absorbs a great deal of heat, warming the roads up to 140 degrees or more,” said Prof. K. Wayne Lee, leader of the URI project. “If we can harvest that heat, we can use it for our daily use, save on fossil fuels, and reduce global warming.”

The article discusses placing water tubes in the road, and then using the warm water to melt ice, heat homes or hot water, or generate steam in power plants.

If you have a hot road, you don’t usually have ice.  It’s going to take a huge system to move heat from a 140F road to heat hot water even to the lowest heated water temperature of 120F.  I don’t know any power plant that uses steam at Th of 140F.

More science and engineering literacy, please.  Just build a concentrated solar power plant in New Mexico and send electricity to people’s water heaters if you want hot water.

This reminds me of those plans to build speed bumps that harvest energy.  The only problem is that the energy you collect is worth less than the value of the speed bump you installed.

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