Thursday, February 28, 2013

Taxing bicycles, poor public policy or a way for cyclists to pay their share?

A recent article on The Atlantic Cities discusses Bicycle Tax:

I personally think taxing biycles at this time when we are working hard to encourage more people to bike is not a good idea. Remember that when someone rides a bike, he/she eliminates many externalities (environmental cost, congestion cost, health cost, etc) from his/her commute. So we can argue that car drivers only pay a small amount of tax for mainly road maintenance but never pay for the externalities they create. Therefore, cyclists are already "paying" by saving.

Last week Democrats in the Washington state legislature introduced a $10 billion transportation package with a number of revenue elements. According to the Seattle Times, the proposal increased the gas tax by 10 cents every five years until it reached nearly half a buck per gallon, created a "car-tab tax" for .7 percent of a car's value, and a $25 sales fee on bicycles that cost more than $500. The latter item was included as "a nod to motorists who complain that bicyclists don’t pay their fair share."
As one might expect, the reaction from bicycle bloggers was swift and sharp, with Streetsblogcalling the bike tax "pointless." A number of strong counter-arguments were raised in the discussion. In explaining why the tax "simply makes no sense," the Seattle Bike Blog pointed to a study showing that riding actually saves local governments money. Cyclelicious noted thedisproportionate nature of a bike tax compared to the excise tax on new vehicles purchases.

Sunday, February 24, 2013

Crime Concentration: Ranking of CTA Train Stops

Using the same logic as in the previous post, I ranked CTA stops based on their crime concentration (type: battery in year 2008 only) at different spatial scales: circles with radius of 0.25, 0.5, and 1 mile around each stop.

For the 0.25-mile circle around the stop, following is a list of the unsafest CTA train stations:

1 King Drive (Cottage Grove-bound)
2 Wilson (95th-bound)
3 Cottage Grove (Terminal arrival)
4 Central (63rd-bound)
5 Howard (Terminal arrival)
6 Ashland/63rd (Harlem-bound)
7 Pulaski (Forest Pk-bound)
8 Chicago/Franklin (Kimball-Linden-bound)
9 Lawrence (95th-bound)
10 Lake/State (95th-bound)

For the 1-mile circle, representing the safety of the neighborhood around the CTA stop, following is a list of the unsafest stations:

1 Laramie (63rd-bound)
2 Ashland/63rd (Harlem-bound)
3 Conservatory (63rd-bound)
4 Cicero (63rd-bound)
5 Pulaski (Forest Pk-bound)
6 Halsted/63rd (Ashland-bound)
7 Pulaski (63rd-bound)
8 Kedzie-Homan (Forest Pk-bound)
9 Central (63rd-bound)
10 Central Park (54th/Cermak-bound)

Interestingly, the two lists are very different. While Laramie, Ashland/63rd, and Conservatory are the unsafest CTA stations with regard to the safety of the 1-mile neighborhood around the station, those stops do not appear in the other list. This suggests that safety characteristics of the neighborhood around a CTA station could be different from the CTA station itself. The graph on the left shows the crime densities of 1-mile circle vs. 0.25-mile circle. Each point represents a CTA station. There is a clear pattern in the data which suggests that for most of the cases, the area closer to the stations have higher crime density (type battery only).

Friday, February 22, 2013

Crime Attractiveness of Transit Stations in Chicago

I have been working with Chicago crime data and its possible correlations with (and effects on) travel behavior for a few months. My recent findings suggest that in Chicago, CTA train stations have higher "crime attractiveness" compared to their surrounding areas. In other words, as moving away from a CTA train station, number of crimes decreases. Note that this only implies correlation and not causation.

The figure on the left illustrates a map of City of Chicago color coded with number of crimes in each Traffic Analysis Zone (TAZ) laid over a map of CTA train stations.

To test the hypothesis that train stations attract crime, I created three buffer zones (with 0.25, 0.5, and 1 mile radius) around each CTA stop and counted the number of "battery" crimes at each circle for every stop. Results show that the average crime density (ratio of # of batteries to area) around CTA stops decreases as moving away from the stop. Average crime density is 42% higher in a 0.25-mile circle around CTA stops compared to a 1-mile circle. There are of course many other factors such as economic activities, crowdedness, etc around transit stations that may play a role. Commonly accepted, certain types of crime like battery occurs where people are and train stations are by nature where people are. However, we can't yet answer the question whether all CTA stops have a high crime rate, or high crime rate areas have a CTA stop?

*Update 1: The map on the right shows crime density (# of battery crimes per area).
*Update 2: The figure below shows crime density (# of battery crimes per area) for three circles with radius of 0.25, 0.5, and 1 mile around a CTA station: As moving away from the CTA train station, crime density decreases. 

Data struggles with the social.

Check out the recent article by David Brook on NY Times about "What data can't do."
"Computer-driven data analysis, on the other hand, excels at measuring the quantity of social interactions but not the quality. Network scientists can map your interactions with the six co-workers you see during 76 percent of your days, but they can’t capture your devotion to the childhood friends you see twice a year, let alone Dante’s love for Beatrice, whom he met twice."

Thursday, February 21, 2013

Map of bicycle racks in Chicago by zip code

City of Chicago recently released an online map of bicycle racks in the city integrated with transit stations.

Here is an example for zip code 60602 in downtown Chicago.

Saturday, February 16, 2013

New concept of shared bus-bicycle exclusive lanes

A shared bus-bicycle exclusive lane might be a little unsafe but innovative and seems promising. Here is a link to their final report:
"This report contains the results of an investigation of the design and operation of shared bicycle/bus lanes in municipalities in the United States and other countries. These lanes are designated for use by public transit buses, bicycles, and usually also for right-turning vehicles. The purpose of such lanes is to provide a time advantage to public transit service by taking the buses out of the general traffic flow and into a designated lane. Where constrained right-of-way prevents provision of a separate bicycle lane, the intent is to allow bicycles to use the designated bus lane. This is to provide a more direct route for bicyclists, provide greater level of service to bicyclists and provide some degree of space separation between general traffic and bicyclists for their greater safety and comfort. However, this combined use raises many issues of compatibility of bicycles and buses sharing the same road space. Researchers found very few examples of state-level guidance on shared bicycle/bus lanes but more examples at the local and regional levels. These are provided in the report. Through surveys and interviews, the shared bicycle/bus lanes from four cities in the United States were selected for in-depth examination and were developed into case studies: Ocean City, Maryland; Minneapolis, Minnesota; Philadelphia, Pennsylvania; and Washington, D.C. As a result of this investigation, an identification and discussion of the contextual factors, design variables, and tools for planning and implementing shared bicycle/bus lanes is presented."

Friday, February 15, 2013

Mobile Depot: TNT New Distribution System

TNT's pedal-assisted electric tricycles are the coolest. In the TNT's new distribution system, mobile depot, "a trailer containing a large number of parcels is towed to a central location in the city during off hours. Parcels are delivered by last-mile drivers in small electric or human-powered vehicles."

Check out this article on The Atlantic Cities:

Thursday, February 14, 2013

The Trouble with Transit-Oriented Development (TOD)

A recent article on Berkeley Transportation Letter discusses the involvement of UC Berkeley faculty and students in a project with the Los Angeles Mayor Antonio Villaraigosa. The objective of the project is to create transit-oriented solutions for the famously car-centric city:
“When people hear ‘transit-oriented development’ they think of a subway stop or light rail station surrounded by rings of ever decreasing density,” he explained. “Tall towers closest to the station, smaller buildings a bit further out, and finally garden apartments.”
In many cases, land use policies cannot be modified to allow this vision. In other cases where policies are relaxed, developing dense nodes in the middle of auto-oriented settings backfires, increasing congestion on roads leading to the very transit stations built to relieve traffic jams.
“Not every transit station needs to be conceived as a perfect ringed city. In fact, in most cases, it won’t work as planned,” he explained. “This is something Robert Cervero has been stressing for years.”

Friday, February 8, 2013

Public Transit for Small Cities

The Streamline Bus system of Bozeman, MT is a good example of public transit service for small cities. They even have a real-time tracker online system which you can see the route maps, real-time arrival times, and real-time location of the buses.
"Streamline's ridership continues to grow beyond expectations. Rides in 2009 exceeded 198,000 and 233,000 in 2010. Rider statistics for 2011 grew again to just over 242,700."

Does relying too much on "Big Data" threaten creative process?

Check out this article on Salon on Big Data and Netflix 
"If Netflix perfects the job of giving us exactly what we want, when and how will we be exposed to things that are new and different, the movies and TV shows we would never imagine we might like unless given the chance?"

Friday, February 1, 2013

Is it irrational behavior, habit, or the comfort of driving that cannot easily be quantified?

A recent article on The Atlantic Cities discusses results of an upcoming paper in Transport Policy on "Car stickiness: Heuristics and biases in travel choice":
"The car effect explains why so many people choose to drive even when it's not in their best interest."