traffic

Slow Down, Speedy

27 Sep 2011

Eyes in the sky are now watching you speed down the eastbound lanes of I-235 between 53rd and Polk. Starting Wednesday, September 28, police will begin issuing tickets for speeds in excess of 10 miles over the limit. Fines are scheduled to be $65 for violations 11-15 miles over the speed limit, $75 for 16-20 miles over, and $80 plus $2 for each mile over 21 mph above the speed limit.

Cameras cover all four lanes, so don't think that you can slide by on the right...

And you had better watch your back driving around the rest of the region as well - there are five additional fixed cameras and one mobile camera placed around Des Moines on a rotating basis. Clive has at least nine on Hickman alone.


View Des Moines Fixed Traffic Camera Locations in a larger map

Despite statements that the cameras are intended to "reduce side impact crashes", it is pretty clear that income is a driving factor (so to speak) in the decision to install these enforcement cameras. Why do I believe this? because they are unmarked. If the intent was truly to reduce crashes and infractions at particularly dangerous intersections, they would be clearly marked with signage at the intersection. Rather there are inconspicuous signs when entering the City - "Photo enforced" on a small white sign on the right shoulder, for example.

By and large, I follow traffic laws. I don't speed, and I am pretty conscious of coming to a complete stop at red lights, so I am not particularly worried about getting tagged. It rubs me the wrong way, however, that the City is disguising what appears to be an income grab at least partially as a public safety measure. It is also disturbing that they outsource enforcement to a private company at a massive profit.

Channel 8 reports that net fixed camera revenues for the first two weeks in September (excluding the I-235 camera) totaled $50,000. Let's say the average citation was $70. That's a whopping 714 citations at five intersections. The private company running the cameras collects $27 per citation, for a gross income of about $38,600 per month or half a million dollars per year (rounding).

The City is poised to collect $800,000 at this rate ($1.3 million in gross revenue less $500,000 paid out to the private camera company). Until I see bright red signs at each monitored intersection, I don't think I'll be convinced that it's about safety over money.

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"Shoot Your Commute"

16 Jul 2010

Experience for yourself the impact that a street full of single-occupancy vehicles has on traffic and congestion!

Urban Ambassadors is bringing together sustainable transportation advocates in Greater Des Moines to recreate the famous Munster, Germany photo (see profile pic) in our fair city. Plus, have a fun after...-party to network and meet crazy, interesting, fellow residents!

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What's the Rush?

16 Jul 2010

Lego Rush HourLego Rush HourOne of the responsibilities of the Des Moines Area Metropolitan Planning Organization is to monitor and report on interstate highway traffic patterns. This data is used to build a long-range transportation plan based on traffic and trip projections.

The Business Record recently published an article analyzing 2009 MPO data (PDF report) that contained a table with morning and evening commute data between downtown and the western junction of I-235 and I-35.

Stick with me through this analysis - am I reading this data right?

The distance from Downtown to the the I-35 junction is 8.3 miles. Of that segment, approximately 5.5 miles is posted at 60 MPH and 2.8 is posted at 55 MPH. Therefore, the legal minimum amount of time it takes to drive from downtown to the western junction is (5.5/60)+(2.8/55)=.143 hours or 8.55 minutes.

Because 8.55 minutes is the fastest one can legally drive the segment of I-235 between downtown and the western junction, I'm going to refer to this as the "legal posted minimum" travel time.

Rush Hour?

According to the MPO data as presented by the Business Record, Des Moines doesn't really have a rush hour.

Actual measured average travel time over this segment only exceeds the legal posted minimum travel time between 7:45 and 8:15 am in the eastbound lanes and between 5:00 and 5:45 pm in the westbound lanes.

It gets even better!

According to the Business Record analysis, the average difference in commute time between the actual measured and the legal posted minimum is a minuscule 15 seconds! In other words, if you drive legally and safely even when you can speed, your commute between the western suburbs and Downtown Des Moines will average only 15 seconds longer during "rush hour".

Of course the speed data also includes those people that put the pedal to the metal once they have an opening in traffic. And, during non-rush hour times, the average speed across the entire segment is above the posted limit. In some areas, significantly above.

Breakin' the Law!

Discussing the data, the Business Record said:

Your absolute best option - if your bosses will allow it - is to get on I-235 at about 7 a.m. and go home at about 4 p.m. Over the course of time, you could save three minutes per day on average. That might not sound like much, but translate that over the course of 10 years, and you can save upwards of five days of your life.

Actually, this is only true if you break the law.

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A recent letter to the editor written by Jon Turner to the Des Moines Register in favor of the MLK extension project falls prey to several commonly-held transportation myths. I want to debunk these myths here.

Come to my Beaverdale neighborhood anytime during peak travel hours and try to cross Beaver Avenue at an intersection that does not have crossing lights.

Traffic control and traffic volume are NOT the same thing. The letter to the editor makes this common error of assuming that reducing traffic volume is the only way to make a street easier to navigate at rush hour. In fact, controlling traffic flow is actually easier than controlling traffic volume - one can plan a control strategy. Volume is a function of a variety of factors, most of which are outside the realm of direct control. What the author can control is his own travel path during known times of heavy traffic.

Adding streets and Interstate connections will NOT reduce overall traffic. It is a commonly known, though not commonly acknowledged, fact that new and widened streets do not reduce congestion. Ironically, they increase congestion due to increasing the total vehicle miles traveled. Until we rethink our underlying transportation system and subsidies for single-occupancy vehicle travel, road additions and widening will remain a game of catch-up.

Let's reduce the number of vehicles speeding through my residential area trying to beat the flow out of town every night.

The author bases his entire argument on the fundamentally flawed assumption that a connector from Downtown through I-80 will reduce traffic through Beaverdale - a neighborhood several miles west of downtown, with no direct street connection. It is just too big a leap to assume that any measurable amount of Beaverdale's through-traffic is people trying to save time by cutting through 6 miles of local streets to get to the northwestern suburbs.

The last time I checked, not one single person lives in the pathway of the proposed extension north of Euclid Avenue.

There are two separate sections of the proposed extension. One section cuts through a protected wetland. The other cuts through an established neighborhood. The author minimizes the impact on the wetlands area (not my area of expertise) and ignores the impact on the actual residential neighborhoods affected by the expansion (my area of expertise).

While there may be valid arguments in favor of the extension, I have yet to hear any that positively and demonstrably benefit the City of Des Moines.

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The Des Moines Register recently published an editorial in part promoting the extension of Martin Luther King drive through a new I-80 interchange to Ankeny. In response, Michael Baldus of the Neighborhood and Natural Recreation Protection Project (NNRP.org) wrote a guest column that was published today.

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A Des Moines Register article today reports that the the Ingersoll fiasco bike lane addition left automobile travel times essentially unchanged. Not only is the street now more accessible to bicyclists, but it was done without substantially impacting automobile travel.

Commute times on Ingersoll Avenue have changed little since traffic lanes were reconfigured, according to city traffic studies...

In the worst case, travel times increased roughly 20 seconds for westbound motorists traveling between Martin Luther King Jr. Parkway and 42nd Street during the afternoon rush hour, said Gary Fox, the city's traffic engineer. There were essentially no changes overall and slight improvements in midday vehicle travel times, he added.

Um, yeah. I probably could have told you that without a GPS-outfitted car, but such technology makes the conclusion a little more believable to the naysayers. Perhaps.

UPDATE, 6/30/2010: A reader who lives just off Ingersoll and commutes every day on the street notes that her commute time has actually decreased!

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