Tag Archive for 'statistics'

Road diet on Nickerson found to improve safety, will other streets get a road diet?

SDOT has released a report on the Nickerson St road diet and found that by reducing the number of lanes for cars, safety has improved. Collisions, overall vehicle speeds, and the number of speeders have been reduced with minimal impact to traffic volumes. The Mayor outlines the good news:

Completed by the City in August 2010, the modifications have produced the following results:

  • Reduced collisions by 23 percent over a one-year period (compared to the previous five-year average)
  • Motorists traveling over the speed limit have declined by more than 60 percent
  • Top-end speeders (people traveling 10 or more miles over the speed limit) have fallen by 90 percent
  • The 85th percentile speed dropped from 40 mph and 44 mph westbound and eastbound to 33 mph and 33 Westbound and Eastbound. This is an 18 and a 24% reduction in speed.
  • Traffic volumes remain roughly the same with no evidence of traffic diversion.

This is the 27th successful road diet implemented by SDOT since 1974. And, with yet another roadway safety measure in place, the question must be asked: why isn’t SDOT implementing more of these safety measures?

We recently pointed out that 28 pedestrians have died in locations that may be eligible for a road diet. Since then, we’ve profiled three streets that may be ideal candidates for SDOT to consider next: 35th Ave SW in West Seattle, 23rd Ave in the Central District / Judkins Park, and S Jackson St in the International District. Let’s compare these three streets with Nickerson St to see whether these other streets may deserve the same successful safety treatment as Nickerson and 26 other Seattle streets.

First, we’ll start by looking at traffic volumes. SDOT looks at the total number of cars that use a roadway before implementing a road diet. Streets with average daily traffic counts above 25,000 are not good candidates, and presumably lower volumes make for better candidates, though road diets have minimal impact on overall volume. Using SDOT’s 2010 traffic volumes, here are the four streets compared, from lowest volume to highest:

  1. Jackson St: ranges from 10,200-13,600
  2. 23rd Ave: 13,400
  3. 35th Ave SW: ranges from 16,100-22,700
  4. Nickerson St: 22,300

Let’s look at another metric. While Walk Score is not an official criteria used by SDOT, it indicates the walkability of a location and is correlated with the number of pedestrians in an area. Streets with more pedestrians may be more deserving of measures that make the pedestrian environment safer and more pleasant. We took a sample Walk Score of 2-3 locations along each of these streets and are ranking them from highest (most walkable) to lowest (least walkable).

  1. Jackson St: 90
  2. 23rd Ave: 86
  3. Nickerson St: 81
  4. 35th Ave SW: 75

While the last two comparisons were interesting, the primary purpose of a lane rechannelization is to improve safety and the most dangerous streets should be looked at the hardest. We looked at this map of nationwide road fatalities, and counted the deaths that have occurred on each of these roadways from 2001-2009 to rank them in terms of urgency for safety improvements:

  1. 35th Ave SW: 4 roadway fatalities (including 2 dead peds)
  2. 23rd Ave: 4 roadway fatalities (2 dead peds)
  3. Jackson St: 3 roadway fatalities (3 dead peds)
  4. Nickerson St: 1 roadway fatality (0 dead peds)

Of our comparison group, Nickerson St has been the safest, is the second least walkable, and has the highest traffic volume. Still, a road diet was implemented and now has been shown to be a success. If a road diet can work there, then surely it can work on these other streets. How many more people will have to die before SDOT implements road diets on 35th Ave SW, 23rd Ave, Jackson St, and other locations where people are killed on Seattle’s roads?


Could road diets have saved the lives of 28 pedestrians?

Walking in Seattle analyzed pedestrian fatality data* from 2001 to 2009 and found that 28 of Seattle’s 90 fatal pedestrian collisions occurred on roads that may be eligible for a lane rechannelization.

A lane rechannelization, or road diet, involves re-striping the roadway, often to add bike lanes or reduce the number of lanes for motor vehicles, with the intent of improving safety by slowing vehicle speeds and shortening crosswalk distances.

Through usually controversial when proposed, 26 road diets have been successfully implemented in Seattle since the 1970s. Streets that have recently been rechannelized include Stone Way, Fauntleroy Way, Nickerson Street, and 125th Avenue. According to pro-pedestrian organization Feet First, “When [road diets are] done properly at appropriate locations, all users benefit.”

One benefit of a lane rechannelization is lowered speed. The road diet on Nickerson Street has dropped motor vehicle speeds from 40-44 mph to 34-37 mph. A pedestrian hit at 40 mph is about 85% likely to die; a pedestrian hit at 30 mph is about 40% likely to die.

Since the road diet on Stone Way, Seattle’s Department of Transportation reports that collisions on that street have dropped by 14%, injury collisions have dropped by 33%, and collisions with pedestrians have dropped a full 80%!

SDOT doesn’t have a specific road diet program, but “we have been using rechannelizations as part of our paving program or proactively as part of other work,” says spokesperson Rick Sheridan. A road diet is a relatively inexpensive and reversible way to compensate for shortcomings of the roadway design and “one tool to improve safety through traffic calming.”

SDOT considers a roadway eligible for a road diet if vehicles routinely exceed the speed limit, if there are a history of collisions on the roadway, and if the lanes can be reduced without significantly impacting the current travel volume. SDOT considers 25,000 vehicles per day as a maximum volume for a four-lane roadway to receive a lane rechannelization.

Walking in Seattle has applied the above criteria to the 104 pedestrian fatalities (a result of 90 collisions) that have occured from 2001-2009 to come up with a list of roads that could be eligible for changes to the roadway striping. We feel that 28 of these collision sites deserve further study by SDOT:

Date of Collision Street Name Neighborhood 2010 Traffic Volume** Walkscore at Fatal Collision
9/12/2001 5th Ave Downtown 10800 100
9/23/2001 SW Alaska West Seattle N/A 86
6/7/2002 S Jackson St International District 13600 83
7/31/2002 35th Ave NE Wedgwood 15400 69
11/2/2002 35th Ave NE Wedgwood 15400 77
1/5/2003 S Jackson St International District 13600 86
6/16/2003 5th Ave Belltown 10800 98
7/3/2003 NE 130th St Haller Lake 19900 37
12/21/2003 Rainier Ave S Rainier Beach 18000 68
10/1/2004 15th Ave NE University District 8900 97
1/5/2005 Swift Way Beacon Hill 7400 71
11/10/2005 E Cherry St Central District 8300 86
12/14/2005 Alaskan Way Downtown 12600 82
2/8/2006 Rainier Ave S Brighton 23900 51
11/2/2006 4th Ave Downtown 18600 98
11/14/2006 SW Admiral Wy Admiral N/A 80
4/21/2007 24th Ave E Montlake 20000 62
10/27/2007 35th Ave SW High Point 20200 65
11/20/2007 16th Ave SW 98146 5100 71
12/19/2007 Pinehurst Wy NE Northgate 10900 86
1/4/2008 23rd Ave S Atlantic 13400 85
3/30/2008 1st Ave S Pioneer Square 24700 83
6/25/2008 Des Moines Memorial 98108 N/A 52
8/10/2008 35th Ave SW North Delridge 22700 48
8/23/2008 E Madison St First Hill 21900 98
9/22/2008 California Ave SW West Seattle 12600 85
6/17/2009 S Jackson St International District 13600 83
11/11/2009 NE 50th St University District 21800 98

Click for a map of locations

23rd Ave S

23rd Ave S, a potential road diet candidate

Many of these roads have four lanes of vehicle traffic and could have a center turn lane added, similar to other road diets. Some of these locations only have two lanes of traffic, like California Ave and Adrmiral Way, however the current lanes are wide and encourage higher speeds. By adding bike lanes and striping the parking lane, the main road space would be constrained and drivers would slow down.

While the city has been falsely accused of waging a “war on cars” through implementation of road diets, these statistics suggest that the city’s efforts have not been aggressive enough at reducing roadway fatalities.


1/3 of Seattle’s pedestrian deaths occur on State and Federal roads

Walking in Seattle has analyzed pedestrian fatality information from the National Highway Traffic Safety Administration’s (NHTSA’s) Fatality Analysis Reporting System (FARS) for the years 2001-2009.

Of the 104 pedestrians that were killed in Seattle during that period, 31 were killed on state or federal highways. While these roadways only cover a small portion of the city, nearly one third of Seattle’s pedestrian fatalities occured there.

By far the deadliest roadway in the city is I-5, with 17 fatalities during the studied period. While most people in their right mind would not consider trying to walk along or across I-5, the freeway cuts a deep path through the city and offers pedestrians no way across for long stretches.

SR-99 / Aurora is the worst state highway in the city, with 7 pedestrian deaths to its name. Other deadly roadways include SR-519 and Lake City Way / SR-522.

While the city of Seattle is responsible for these state highways, funding is not available to re-build these streets as complete streets.

The high rate of fatalities on these roadways is indicative of a few things. While these roads don’t cover a lot of area in the city, they do carry a lot of vehicles, increasing the chances of driver-pedestrian encounters. These highways are also the city’s longest, so they are statistically more likely to show up in a list. More importantly, though, these roadways show a disregard for active transportation. Highways and walkers don’t mix well, as these statistics remind us.

Click here for a searchable map of pedestrian fatalities from Transportation for America.


Crosscut: SPD enforcement inconsistent with collision data

Former Washington state Secretary of Transportation, Douglas MacDonald, has a post on Crosscut that examines some of the city’s traffic fatality data, asking how safe are Seattle’s roads?. He points out that the number of fatalities for pedestrians is much higher than that of bicyclists:

The numbers are stark, starting with the death toll. In the three years 2008–2010, there were 62 traffic fatalities in Seattle. More than half involved pedestrians (25 deaths) and cyclists (7 deaths). Just to put the scale of traffic victims against the scale of crime victims, that toll of 62 deaths on the roads compares to the three-year Seattle homicide total of about 70, so long as you, like the Seattle Police Department, don’t drag in another half-dozen “officer involved” shootings.

It’s a great write-up, pointing out that elderly pedestrians are more at risk, and that collisions with pedestrians and cyclists account for 10% of all collisions between moving traffic. And, he reinforces what we reported on yesterday:

Cutting through the huge variety of circumstances in all these collision, the data reported by SPD points in one dramatic direction. Three-quarters of vehicle collisions with pedestrians and cyclists in 2009 and 2010 involved the actions of the driver as a contributing factor. In two-thirds of those cases (about half of the total) the problem was the most basic of driver derelictions: failure to yield the right of way to the pedestrian or cyclist. So, with a myriad of steps that can be taken to improve safety, the most fundamental lie with getting the drivers to mind the rules.

This creates a very troubling juxtaposition with what the statistics show concerning traffic enforcement. In 2010 the Seattle Police Department issued 27,348 traffic tickets for moving violations. This was down by 7 percent from 2009. In 2010 just 197 tickets were issued to drivers for failing to yield the right of way to pedestrians. That was down by over 50 percent from 2009. SPD did, however, issue 1570 citations to pedestrians in 2010. That was up from 1274 in 2009. That picture might suggest that the enforcement priority lies with picking the low-hanging fruit rather than focusing on the heart of the problem.

The article recommends attending a road safety summit – there are two left.


Ped collisions in 2010 second highest in last 10 years

SDOT has released its annual traffic collision report on Friday. Pedestrian collisions were up, last year, to 529, the second highest rate in the last 10 years. However, pedestrians were injured in a lower percentage of collisions than normal, and only 5 pedestrians were killed, the lowest since 2002. While conclusions can’t be drawn from one year, one could hope that a drop in injuries and deaths would continue from drivers going more slowly.

Overall, vehicle traffic volumes were slightly up for the year. The city counted fewer pedestrians walking downtown last year, but has since switched to a more thorough and standard pedestrian-counting methodology that will be used starting this year.

There is a lot of missing data with regard to pedestrian collisions, however where data was available for drivers, 256 of them did not yield the right of way to pedestrians, which was the biggest cause of pedestrian collisions.

The report indicates that SPD and SDOT work together to target enforcement efforts. According to Acting City Traffic Engineer, Brian Kemper, “When we [SDOT] have locations of concern, we work with SPD…and provide the engineering or traffic solution that is appropriate.” The improvements the city has made, “have been pretty effective,” but it requires a team effort between SDOT and SPD of education, engineering, and enforcement.

SPD did conduct 42 pedestrian safety emphasis patrols, where a plain clothes officer acts as a pedestrian crossing the street legally, and 48 violations were written as a result of these stings.

Though the leading cause of pedestrian collisions is drivers failing to yield the right of way, SDOT issued 8 times more infractions against pedestrians than they did against drivers failing to yield the right of way to pedestrians. In fact, the violations issued to drivers for failure to yield to pedestrians in 2010 was down to half of 2009’s level. Also, remarkably, the number of citations issued in school zones were dropped by over 60%.

SPD does deploy a van to monitor speeds in school zones from state funding authorized in 2009, resulting in the issuaance of 1,808 citations last year, averaging a decrease in speed of between 5 and 10 miles per hour in school zones.

The report provides statistics related to the lane rechannelization at Fauntleroy Way SW, and shows that collisions dropped by 31% and injuries dropped by 73%. Rush hour travel time for drivers did increase by 4 to 65 seconds from Alaska to California Ave.

Also, since 2006, more pedesrian collisions have happend in November than any other month.

The Seattle PI has a general recap of the report, as does PubliCola.

A link to the final report can be found here


2009 Pedestrian Collision Statistics

SDOT recently released their 2009 Traffic Report, which shows that there were 479 pedestrian collisions in Seattle that year. This was the first full year of data since SDOT began implementing recommendations from the Pedestrian Master plan, and the number of pedestrian collisions per capita dropped to the lowest level since 2004. Pedestrian collisions have increased over the past 10 years, but not at a greater rate than the population.

There were 24 fatalities on Seattle’s roads in 2009, and 11 of the people killed were pedestrians. This ties with 2003 for the most pedestrians killed in a year during the decade. Most of the fatalities occurred on major arterials and most were at intersections.

Another interesting fact is that the Seattle Police Department issued 1,274 citations for “pedestrian infractions”, which I can only interpret as things like jaywalking. They issued only 409 citations to drivers for not yielding the right of way to pedestrians. There were, however almost 30,000 citations issued to drivers in 2009, more than 20,000 of which were for speeding.

The main contributing factor in 45% of collisions was the driver’s failure to yield the right of way to the pedestrian and in 58% of collisions the pedestrian was not at fault. However, that means that in 42% of collisions there is something the pedestrian did to contribute to the crash. The most common thing was that the pedestrian was outside of the crosswalk. In several cases the person on foot disregarded the stop light or did not grant the right of way to the vehicle.

There was one instance of a pedestrian being hit apparently while sleeping.

Most collisions happened between 5-6 pm. The months with the most pedestrian collisions were November, December, and January, which accounted for over a third of the year’s collisions.

The statistics also show that people aged 5 through 24 account for a disproportionately high number of injuries.

The report shows pedestrian accidents throughout the city, with the majority occurring near downtown. Arterials like Rainier Ave, Madison, Lake City Way, and 15th Ave NE had several collisions each.

Tom Fucluoro has written two great write ups – one on Capitol Hill Seattle and the other on Seattle Bike Blog. Or, browse the report below to see more data:

2009 Traffic Report


479 Vehicle-Pedestrian Crashes in 2009

Erica at PubliCola shares some statistics from SDOT in 2009:

  • Car collisions with pedestrians were also down, but they remained more common than bike collisions, with 479 crashes (11 of them fatal) last year alone. Sixty-eight percent of the time, the pedestrian was hit in a crosswalk (just 8 percent of all crashes were pedestrians crossing intersections against the signal).
  • Although pedestrian and bike collisions were the most likely collisions to be fatal (accounting for 11 of 24 fatalities), overall, driving a car remains the most dangerous way to get around. Ninety-three percent of all accidents in 2009 were between cars or cars and stationery objects (like parked cars, which accounted for 24 percent of all car-on-car crashes, or things like phone poles and street signs, which made up another 6 percent).
  • Finally, the data suggest that if you’re going to get drunk, just stay home. Although just one cyclist was hit by a drunk driver in 2009, five drunk cyclists were involved in crashes, along with 11 pedestrians. (Two pedestrians “had taken medication,” one was under the influence of drugs, and one was “apparently asleep,” according to the report.

While it’s good that pedestrian accidents declined in 2009, accident and fatality numbers are still way too high. 251 of these accidents were at least partially the fault of drivers. With driving on the decline, hopefully these accidents will continue to decrease. But more vigilant prosecution of dangerous driving, as well as some changes to protect pedestrians (e.g. disallowing right-on-red in some locations), could help make Seattle a safer place to walk.


Pedestrian safety statistics may be misleading

The Seattle Weekly takes a peek at statistics on pedestrian safety and points out that they may not be entirely accurate.

For one thing, most jaywalkers who get hurt are, in fact, drunk off their ass — “as the National Highway Traffic Safety Administration notes, ‘about 25 percent of fatally injured pedestrians have a BAC greater than .20′” — a condition for which there is already another law on the books.

The blog post also references an article in Slate defending jaywalking, which adds to some of the questions we raised here about the illegality of jaywalking.