Wednesday, August 28, 2013

Road Safety -- North Decatur Road (Part II)

Share and share alike: room for everyone on North Decatur Road.
Here are some info nuggets from the July 29 workshop:
  • Many of our road standards (e.g., sign height) are relics of the original studies conducted in the 1950’s. Consider 1950’s road conditions, vehicles (size, materials) vs today’s cars and driving habits.
  • Pedestrian deaths are proportional to impact speed. A 20 mph impact has a 5% death probability for the pedestrian; at 30 mph, those odds go to 45%; at 40 mph, 85%. {Thanks to Marian at PEDS for correcting the above figures and adding that "It’s amazing that doubling one’s speed means a seventeen-fold increase in risk of fatality and also speaks to why we at PEDS are so focused on getting drivers to slow down. More information on speeding in urban and residential districts can be found on our website:"}
  • Intersections are the most dangerous place for pedestrians.
  • Most people have trouble judging distances, and people tend to drive at what they consider a “comfortable” speed (as opposed to the posted speed limit). The combination—a speeding driver who overestimates his/her ability to stop—is deadly. 
  • Cyclists: riding against traffic is dangerous because it places the cyclist in an area outside the driver’s expectation.
  • EVERYONE is a pedestrian at some point: while getting out of a car in a parking lot, while leaving a bus or building. Of the US’s ~300 million population, around ~200 million hold drivers licenses. Children, the elderly and the impaired are often, by necessity, pedestrians.
  • Crossing lights are timed to a 3.5 foot/second standard (the old standard assumed people would walk at ~4 foot/second). Not all individuals are able to travel at this idealized speed, which means they may not have enough time to cross even when they use crosswalks correctly. 
  • If foot traffic is vital to business, protect foot traffic.  
  • The young and the elderly have slower reaction times than adults. 
  • The young and the elderly have limited peripheral vision (30% less) relative to adults.
  • Intersections are dangerous. The biggest number of crashes at intersections are due to left turns, with right turns being the second most dangerous turn.
  • Crash sources: ~64% are human factors, ~28% are due to road/environmental conditions, ~9% are due to vehicular malfunctions.
human factors [drivers go too fast, drivers are stressed during commutes, drivers allow themselves to be distracted by their cell phones (talking or texting/browsing web)] 
environmental factors (drivers may not notice they are picking up speed on the downhill; limited visibility due to topography, weather, light conditions; tunnel vision due to distractions)  
North Decatur Road at rush hour is a minefield... 
  • Maintenance is one of the first things that suffer during budget cuts. Overgrowth of vegetation can create road hazards.
  • With regards to cyclist fatalities, roads without bike lanes pose the highest danger. Sidewalk riding increases the risk of crashes. 
  • Bikes belong in highways unless prohibited.
  • An ideal bike lane (one way) is 4’ wide.  When a bike lane is added next to a parking lane, the overall lane width should be 12’ (to shelter cyclists from car doors that suddenly swing open). A 10-11’ lane can be equally safe, if posted speeds are 45mph or less. 
  • North Decatur Road moves around 19,000 vehicles/day. Likely solutions for existing situations include a road diet or reversible lanes.
  • For pedestrian safety: make eye contact with drivers and never assume that  “waving” signifies that the whole passage (across whole roadway) is safe. 
  • Faster speeds and busy roadways create tunnel vision for the driver. The busier the road and the faster the speed, the smaller the area that the driver is aware of (peripheral perception suffers!).
Links from the presentation: a treasure trove! Pedestrian and Bicycle Information Center
Includes a report titled Road Diet Conversions: A Synthesis of Safety Research (May 2013)
"The primary purpose of this review is to assess the available evidence regarding the safety effectiveness of reductions in the number of motorized traffic lanes, widely known as road diet conversions. Although road diets have been implemented since at least the 1970s, earlier reviews and a search of the literature identified no controlled safety evaluation studies conducted prior to the year 2002. A systematic search of literature dating from 2002 was conducted. Six studies in total were initially identified, with four serving as the basis for most conclusions in this review."
This site also includes the PBCAT (Pedestrian/Bike Crash Analysis Tool).

APBP (Association of Pedestrians and Bicycle Professionals)
Includes the Women Cycling Project and the Bicycling Parking Guidelines document [pdf]

NCHRP (the National Cooperative Highway Research Program)
Want to know the outcomes of research projects funded by the Transportation Research Board of the National Academies? Check out the project list.
"The National Cooperative Highway Research Program (NCHRP) conducts research in problem areas that affect highway planning, design, construction, operation, and maintenance nationwide"
PEDSAFE (Pedestrian Safety Guide and Countermeasure Selection System)
Don't miss their recommendations for sidewalks/walkways, crosswalks, or their case studies (featuring examples grouped by state/country and also by countermeasures--great set of examples of what's available).
"The Pedestrian Safety Guide and Countermeasure Selection System is intended to provide practitioners with the latest information available for improving the safety and mobility of those who walk. The online tools provide the user with a list of possible engineering, education, or enforcement treatments to improve pedestrian safety and/or mobility based on user input about a specific location."
BIKESAFE (Bicycle Countermeasure Selection System)
Yet more great info, including crash factors.
The Bicycle Countermeasure Selection System (BIKESAFE) is intended to provide practitioners with the latest information available for improving the safety and mobility of those who bicycle. The information on the site falls into two categories, Resources and Tools
US Department of Federal Highway Administration's Safety Program
"The focus of the FHWA Safety Program is to ensure safer roadways The FHWA Office of Safety works with Federal, State and Local partners and others in the transportation community to develop and promote programs and technologies to improve the safety performance of our Nation’s roadways to reduce the number of fatalities and injuries (safety facts). Safety should be integrated into all programs and projects and considered every time and during every stage from development to completion.  This office provides decision-makers the tools, resources, and information necessary to make sound safety investment decisions."
National Highway Traffic Safety Administration
Don't miss the "Everyone is a pedestrian" section.
"NHTSA was established by the Highway Safety Act of 1970 and is dedicated to achieving the highest standards of excellence in motor vehicle and highway safety. It works daily to help prevent crashes and their attendant costs, both human and financial."
Institute of Transportation Engineers

Safe Routes to School
With Druid Hills High School being so close to North Decatur Road, that's another reason to focus on pedestrian and cyclist safety.

CDC's Pedestrian Safety site.