Guest Post: A detailed look at commuting mode share in Los Angeles, and how bikes lanes fit in

Not many people have the ability, or patience, to dig deep into various data sources to paint a detailed picture of just how people get to work in the City of Angeles.

And how bicycles fit into that portrait.

Dennis Hindman does.

He’s written a number of detailed analyses for this site, including a look at the causes of bike-involved collisions, and how the economy and bike lanes affect them.

Today he offers a look at the influence of bike lanes on LA commuting rates in the context of the overall commuting picture.

It’s fascinating stuff, and worth a few minutes to read. And maybe bookmark for future reference.

I’ll be back tomorrow with our usual Morning Links.

………

In 2008, there were 147 centerline miles of bike lanes in the city of Los Angeles, according to League of American Bicyclists survey results from 90 of the largest U.S. cities.

The Los Angeles Department of Transportation substantially increased the centerline miles of bike lanes installed per calendar year after the 2010 bike plan was approved by the LA city council in 2011. The centerline miles of bike lanes is now at least 375, according to the bikeways inventory listed on the website ladotbikeblog. Which is 2.55 times more than in 2008.

Chart-1

There have been two periods of time since 2005, using Census Bureau household survey results (ACS), where the bicycle commuting percent of workers residing in the city of Los Angeles has increased. One was 2008 through 2009 after there was a sharp increase in the price of gasoline in 2008. Interestingly, the bicycle commuting share increased further in 2009 after the price of gasoline dropped, then dropped by 10% in 2010 (within the margin of error) and increased back to 1% in 2011 and 2012. According to the margin of error for the ACS results, it’s possible that the 2009 percent could be .9% as it is for 2010 and 2008, and then rose to 1% in 2011. Although if you look at the LAPD collision reports during that time, the bicycle collisions sharply increased in 2009 compared to 2008.

The number of bicycle commuters increased by an estimated 46% from 2007 through 2010.

Compare that to 2011 through 2014, when there was a 41% increase in the number of bicycle commuters and nearly 200 miles of bike lanes were installed.

There was a 143% increase in the ACS estimated number of bicycle commuters in the city of Los Angeles from 2005 through 2014 and a 9% increase in the amount of workers commuting by car, truck or van. Commuting by transit increased 15%.

Chart-2

Chart-3

When the number of bicycle commuters increased by 46% from 2007 through 2010 in the ACS results, the motor vehicle involved bicycle collisions reported by the LAPD increased by 61%.

If the installation of almost 200 miles of bike lanes from 2011 through 2014 had either decreased, or had no effect on the overall level of safety for bicycle riding on streets, then the number of motor vehicle involved bicycle collisions reported by the LAPD should have substantially increased based on the greater number of bicycle commuters — as happened from 2007 through 2010 when much fewer additional miles of bike lanes were installed.

It turns out that the LAPD reported motor vehicle involved bicycle collisions went from an increase of 7% in 2012, to less than a 1% increase in 2013 and a 6% decrease in 2014.

Chart-4

Traffic collisions and fatalities reported by the LAPD are given to the California Highway Patrol and these results can be obtained through their SWITRS data, as I have done for the chart above and below. These data collection results are about 7 months behind from when the collisions took place. Even given the incomplete data for 2015, the number of bicycling fatalities reported by the LAPD is already the second highest since 2001.

Chart-5

For comparison, here is my estimated number of car, truck and van commuters derived from ACS survey results on percentage chart S0801.

Chart-6

Also, the estimated percentage of workers who primarily commuted by car, truck or van and resided in the city of Los Angeles. Notice how the percentage has remained relatively stable from 2008 through 2014.

Chart-7

The ACS estimated number of transit commuters has not yet increased to the amount that it was in 2008, even though the estimated number of workers has increased by 3%. Metro’s transit boarding’s throughout the county decreased by 2.8% in calendar year 2014 and continued to fall through August of 2015.

Chart-8

The percent of workers residing in the city of Los Angeles who primarily use transit to commute. Metro transit rail boarding’s, along with bus boarding’s, fell in Los Angeles County in calendar year 2014. It might seem that increased bicycle commuting took away from rail ridership, but the average bicycle trip tends to be a shorter distance than an average transit rail trip. These two forms of transportation would tend to be more complementary, rather than competitive with each other.

Chart-9

The percent of workers residing in the city of Los Angeles who primarily work from home has increased from 2005 to 2014, probably due to greater use of the internet.

Chart-10

The last category of journey to work on the ACS data is primarily commuting by motorcycle, taxi or other means.

Chart-11

Adding together the ACS estimated percent of workers residing in the city of Los Angeles who primarily commuted by walking, bicycling or transit has, except for 2011, remained fairly stable from 2007 through 2014. I didn’t calculate the margin of error for this category.

Chart-12

……..

Dennis adds a few final notes on how he compiled the data and graphs.

I’ve tried to simply give data available from SWITRS, ladotbikeblog and ACS in the form of graphs. This is so that anyone can check the accuracy of this information quickly on-line. Unfortunately, to make it as unbiased and the changes between years as clear as I can, I created separate charts for each category. Combing categories made each category more of a straight line.
I used the Census Bureau American Community Survey chart S0801 which gives results in percent of workers and converted that into the number of workers using each type of transportation for journey to work. There are two other charts that give the estimated number of workers for each type of transportation, but they do not include the year 2005–which S0801 does.

 

 

 

 

 

 

Leave a Reply

Your email address will not be published. Required fields are marked *

%d bloggers like this: