Category: People

Survivor bias: Who walks away from automobile crashes?

February 14, 2013 / / 6 Comments

This photo of a damaged car has little to do with this post. 

Then my friend Alex E. asked, “Is there a reason why?”

I can’t leave such a question hanging. I thought I read that somewhere, and it was probably in Tom Vanderbilt’s book, Traffic. What I found in there mostly referred to trucks (the semi-trailer type) because of their mass and how people not driving trucks behave around them on the road. The second part explained the statistics around who lives and dies in crashes involving a drunk driver.

Knowing that, and knowing the story I tweeted a link to, you’ll see that the event didn’t involve a truck and my relating them was perhaps unsuitable. It did involve drunk driving, but I may have misread the book text.

Here’s what Traffic says about trucks

“When trucks and cars collide, nearly nine of ten times it’s the truck driver who walks away alive.” Vanderbilt discusses how that is (page 247).

…we all likely have proof of the dangerous nature of trucks. We have seen cars crumpled on the roadside. We’ve heard news stories of truck drivers, wired on stimulants, forced to drive the deregulated trucking industry’s increasingly long shifts. We can easily recall being tailgated or cut off by some crazy trucker.

Just one thing complicates this image of trucks as the biggest hazard on the road today: In most cases, when cars and trucks collide, the car bears the greater share of what are called “contributory factors”.

Really? Car drivers caused crashes with trucks and then die from it?

Instead of relying on drivers’ accounts, he [Daniel Blower at Michigan Transport Research Institute] looked at “unmistakable” physical evidence. “In certain crash types like head-ons, the vehicle that crosses the center much more likely contributed to the crash than the vehicle that didn’t cross the center line”.

After examining more than five thousand fatal truck-car crashes, Blower found that in 70 percent of cases, the driver of the car had the sole contributing responsibility in the crash.

Basically, the car drivers in a car-truck crash caused the crash and ended up being the ones dying.

…the reason trucks are dangerous seems to have more to do with the action sof car drivers combined with the physcial characteristics of trucks and less to do with the actions of truck drivers. “The caricature that we have that the highways are thronged with fatigued, drug-addled truck drivers is, I think, just wrong”, Blower said.

“In a light vehicle, you are correct to be afraid of them, but its not because the drivers are disproportionately aggressive or bad drivers”, Blower said. “It’s because of physics, truck design, the different performance characteristics. You can make a mistake around a Geo Metro and live to tell about it. You make that same mistake around a truck and you could easily be dead.”

What Traffic says about drunk driving

Of the 11,000 drunk-driving fatalities studied by economists Steven D. Levitt and Jack Porter, 72% were the crash-causing drunk driver or their passengers, and 28% were the other drivers (most of whom were not drunk themselves) (page 251).

Destination streets are rarely the best places to bike

January 29, 2013 / / 22 Comments

This family took to riding on the sidewalk of Division Street instead of in the bike lane. They’re riding the stylish workhorse WorkCycles Fr8. Once I saw them riding the blue one, I had to get a different color. 

My friend Calvin Brown, a circumstantial urban planner, is always giving me Jane Jacobs-style observations about how citizens use their cities.

“Destination streets are the ones I avoid biking on because there’s so much car traffic there. Traffic must be balanced between streets that are good for biking and ones that aren’t currently good.”

In other words, because it’s a destination street (a place where there are a lot of retail outlets, venues, points of interest) it induces a lot of car traffic. Lots of car traffic discourages people from riding bikes, and makes it difficult for those who already are.

To me, a great example of this is Division Street. There’s a bike lane there from Ashland to California Avenues, and has tons (tons!) of restaurants and some night clubs. Yet that causes a lot of taxi traffic, people driving their own cars, looking for parking, jutting into the bike lane to see why traffic is going slow or backed up (um, because there are ton of cars!), and valet and delivery drivers blocking the bike lane.

It’s exactly this traffic, though, that keeps these places vibrant, desirable, and healthy (from an economic standpoint). The solution for bicycling is easy: swap the car parking with the bike lane so that bicycling isn’t affected by a majority of the aforementioned traffic maneuvers.

Calvin’s “destination streets” examples were Grand Avenue and Chicago Avenue. Neither has bike lanes, and both have 2 travel lanes in each direction. Grand has destinations from Racine Avenue to Ashland Avenue and Chicago has destinations from Ada Street to Western Avenue. I’d wager that if you narrowed those roadways by installing a protected bike lane you’d get slower traffic and higher business receipts.

Chicago Avenue at Hoyne Avenue is a particularly stupid part of Chicago Avenue: The Chicago Department of Transportation installed a pedestrian refuge island here. After several years and at least 4 replaced signs due to collisions of automobiles with it, the design hasn’t been modified. The island in and of itself did not change the speed of those who drive here, as the roadway’s width remained static.

Mapping guns in your town: is that okay?

December 25, 2012 / / 6 Comments

This screenshot shows the pistol permit holders in Westchester County, New York. The highest density of permit holders appears to be at the border with Bronx County, also known as the northern edge of New York City. 

An ABC News story I read through the Yahoo! News website tells about The Journal News, covering Westchester (Yonkers, New Rochelle) and Rockland (New City, Pomona) counties in New York, posting the names and addresses, on a map, of gun permit owners. The map contains:

…the addresses of all pistol permit holders in Westchester and Rockland counties. Each dot represents an individual permit holder licensed to own a handgun — a pistol or revolver. The data does not include owners of long guns — rifles or shotguns — which can be purchased without a permit. Being included in this map does not mean the individual at a specific location owns a weapon, just that they are licensed to do so. [Notice that some dots are outside the county.]

This article is interesting to me for two reasons:

1. The article has hyperlinks to the (alleged?) Facebook profiles of two people who commented on The Journal News’s website. I predict this will only become more common. I don’t have a Facebook profile to link to.

2. The rationale to make a map seems reasonable: so people know where there are potentially guns in their neighborhood. It seems reasonable that people want to know where there are potential sources of danger and harm near them.

The names and addresses were obtained through “routine” (their words, not mine, but it is pretty routine and normal) Freedom of Information Act (FOIA) requests. The quantity and types of guns are not considered to be public record, although this may not be true, according to the ABC News article.

Customer reviews for my bike map app

July 15, 2012 / / 0 Comments

Only reviews left for the current version are displayed on the iTunes Preview page, and the default view of the iTunes Store. 

I’m appreciative of the two reviews people have left for my app – it’s a bike map for Chicago stored in your phone, download in iTunes. Their positivity and the slight increase in sales this past week has increased the ranking of my app. I don’t know what the ranking means.

When my app first ranked, in its Reference category, it was 385, then 289, and now stands at 315. I’m not sure on what factors the ranking is based, but I’ve gathered some clues from other bloggers:

[In addition to the number of downloads, other] factors play into the ranking equation such as how long the app is opened as the active app and how often the app is opened.

There’s no mention of reviews on that page, but I found another article that mentions more ways to improve your app, which includes having positive reviews. (Another factor it mentions is frequently updating the app.)

I’d like to hear from my app’s users what their feedback is before they leave a review in the iTunes Store. I can address issues directly with users and discuss how they can (or cannot) be incorporated in a future update to the app. You can send your feedback to me, and your love to the app store. (A major downside of the customer reviews process in the iTunes Store is the inability for the developer to respond.)

My app’s received two reviews (both 5 stars!) so far:

Saw this app being discussed on Twitter and thought I’d check it out. So, on the hottest day of 2012, I jumped on my bike and rode around my area checking out the apps features. Color me impressed! I rode to a few areas that I was not over familiar with and activated the app to peruse my options via my bike (or CTA). I look forward to using this on my far south/far north bikiing adventures soon!

The first reviews about the first version:

Would be great if it could locate on the map with GPS. Also if it could zoom out more. These bike lanes have come a long way recently. There are some really nice new places to ride like the cycle track on Kinzie. But there are also some old routes out there that are great biking such as the Boulevard System (Humboldt, Logan, Palmer Sq) that you could show on your map. And it says it supports German, but it is in English 🙂

The part about my app being available in German was true for v0.1, but I’ve fixed that for v0.2. If you’re going to leave a review, I’d like to leave you with this advice, for I feel it makes for a constructive review:

  1. Describe what is good about the app, and what you like about the app.
  2. Describe how you’ve used the app.
  3. Suggest ways the app could improve.

This was what the first version looked like. It wasn’t very good. 

Brief history of suburbs and sprawl, according to Taras Grescoe’s “Straphanger”

June 29, 2012 / / 0 Comments

The Metra station in Riverside, Illinois, a version 1.0 streetcar suburb designed by Frederick Law Olmsted and Calvert Vaux. 

I’m reading another book a publisher sent to me. It seems pretty biased, and it’s biased in the direction I already feel, so it’s really easy reading. But it seems that people like me are its only audience and that it assumes I’m already pro-cities, anti-suburbs and maybe even anti-car. Definitely not a book that’s going to espouse the benefits of transit to those who don’t use it, don’t want to use it, or are on the fence for either situation.

If I could get my father or brother to read this book, that would be an accomplishment just short of a miracle.

The book is Straphanger: Saving our cities and ourselves from the automobile, by Taras Grescoe. I really like the section I just finished reading, a “condensed history of sprawl”. I had recently “argued” with my father about the development of the subdivision he lives in, east of Phoenix. He posited that suburbs were the result of consumer desires. Grescoe writes to the contrary. Here we go:

The origin of the Anglo-American suburb has been traced to Clapham, five miles south of London, where, in the 1790s, Evangelical Christians eager to remove their families from the evils of the city began living in what had formerly been their weekend villas, and commuting to the City by private carriage. In the United States, [author Kenneth] Jackson dates the beginning of the process to 1815, when regular steam ferry service to Manhattan made Brooklyn Heights the nation’s first true commuter suburb. (page 89)

American suburb version 1.0

  • When: 1853 onward
  • What it was: picturesque, full of green space, near central cities, attached by rail line
  • Who lived there: As mortgages didn’t exist, only those who could afford to buy a home outright
  • Examples: Llewellyn Park, NJ; Riverside, IL.
  • Note: Ebenezer Howard’s “Garden City” design is related.

American suburb version 2.0

  • When: Post World War II
  • What it was: cheap, small housing on vast land tracts; pre-assembled homes
  • Who lived there: Families with soldiers that expanded quickly so new homes were needed fast.
  • Examples: Levittown, Long Island; Lakewood, Los Angeles.
  • Note: “The prevailing myth”, writes Kenneth Jackson, “is that the postwar suburbs blossomed because of the preference of consumers who made free choices in an open environment. Actually, most postwar families were not free to choose among several residential alternatives. Because of public policies favoring the suburbs, only one possibility was economically feasible”.

American suburb version 3.0

  • When: Late 1980s, 1990s to now
  • What it was: Found near office parks, also known as “edge cities”, “common interest communities” (gated and homeowners associations)
  • Who lived there: Single races (self-segregating), people who lean conservative
  • Examples: Silicon Valley, Nevada, Florida
  • Note: Under the George W. Bush administration, Fannie Mae and Freddie Mac offered easy credit and homeownership rate rose to 69% by 2004. “(By 2012, it is expected to drop to 62%, the lowest level since 1960.)”

American suburb version 4.0

  • When: 2008, easy credit crisis, underwater mortgages
  • What it is: Least glamorous, the clichéd image of the inner city has moved to the suburbs. Arizona has highest rate of property crime. Nevada and Florida, the most suburbanized states, have highest rates of violent crime (Florida also has highest rate of pedestrian and bicycle fatalities).
  • Who lives there: A diverse group of people.
  • Examples: See “What it is”
  • Note: “Humans are social animals. I [Kenneth Jackson] think the biggest fake ever perpetrated is that children like, and need, big yards. What children like are other children. I think we move children to the suburbs to control the children, not to respond to something the children want. In the city, the kids might see somebody urinate in public, but they’re much more at risk in the suburbs, where they tend to die in cars.”

What are those public policies as described in American suburb version 2.0?

The federal government had carrots and sticks. Carrots were subsidies for homeownership (could be deducted from income taxes) and no down payment required for returning soldiers. Sticks included redlining (racial segregation), propagated by the Federal Housing Administration and banks. Zoning was another stick, which dictated what could go where.

Another carrot was the federally-funded highway system, the “greatest public subside to private real estate in the history of the world”.