Short answer: Yes, collisions are down 38% since the City added safety measures

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The City and community members took several steps to increase pedestrian safety in West Hollywood crosswalks, after deaths in 2013 and 2014. Starting in October 2014, the City launched a public information campaign, enforcement efforts, and safety messages on variable message boards. By January 2015, in-street signs and reflective pavement markers had been installed at 10 crosswalks. The City also began planning for traffic signals at five crosswalks.

Given those efforts, are West Hollywood crosswalks safer today? The City staff counted the number of collisions involving pedestrians crossing the street, before and after the changes. The before counts were 53 in 2013 and 36 in 2014. The after counts were 26 in 2015 and 12 in the first four-and-a-half months of 2016.

For ease of comparison, we converted the City’s counts to monthly averages. Before the changes, there were 4.4 collisions per month in 2013 and 3.0 in 2014. After the changes, there were fewer collisions: 2.2 per month in 2015 and 2.7 per month for the beginning of 2016.

Sources: City of West Hollywood, Crosswalk Safety Update, staff report to City Council, June 20, 2016; our analysis.


Reduction in collision rates in West Hollywood crosswalks

We calculated the change from before the safety measures to after. We combined 2013 and 2014 into “before” and 2015 and early 2016 into “after.” The number of collisions per month dropped 38%. The reduction was statistically significant.

The chart below shows the reductions at different kinds of crossings.

Notes: We tested whether the changes were statistically significant using a “comparison of Poisson rates” (collision rates, in this case). The test produced a “p-value,” the probability of randomly seeing reductions this big or bigger if the underlying collision rates hadn’t really changed. A p-value of 5% or less is often described as statistically significant. The p-values were 1% for total collisions and 5% for crosswalks with in-street signs. The other p-values were higher. Sources: Same as above.


Effectiveness of in-street signs

in street signThe biggest percentage reduction in collisions was at mid-block crosswalks with the new in-street signs. Collisions dropped 76%, which was statistically significant. Those crosswalks had 13% of the collisions before the signs were installed and only 5% afterward.

We wondered if other communities had also found in-street signs to be effective. The chart below is one example, from a government-funded academic study. It shows the yield rate — the percentage of drivers who stopped for pedestrians — for crosswalks with various safety measures.

The most effective measures (in the upper left corner) were traffic signals. In-street signs came next (we circled them in red). Drivers were less likely to yield in crosswalks with the other measures, such as flashing beacons and signs that weren’t in the street.

201606 signs nchrp 562 figure 24

Source: Improving Pedestrian Safety at Unsignalized Crossings, Transportation Research Board, 2006.


http://wehobythenumbers.com/wp-content/uploads/2016/06/201606-crosswalk-1024x670.jpghttp://wehobythenumbers.com/wp-content/uploads/2016/06/201606-crosswalk-300x300.jpgDavid WarrenPerformance (effectiveness)Transportationwalking
Short answer: Yes, collisions are down 38% since the City added safety measures| The City and community members took several steps to increase pedestrian safety in West Hollywood crosswalks, after deaths in 2013 and 2014. Starting in October 2014, the City launched a public information campaign, enforcement efforts, and...