4. Don’t hate, Decelerate!
Speed limits and how we get
them.
■ The 85th percentile rule:
The maximum speed limits posted as the result of a study based
primarily on the 85th percentile speed.The 85th percentile speed
is a value that is used by many states and cities for establishing
regulatory speed zones.
■ Speed LimitTheory:
Use of the 85th percentile speed concept is based on the theory
that:
the large majority of drivers are reasonable and prudent.
Do not want to have a crash.
Desire to reach their destination in the shortest possible time.
A speed at or below which 85 percent of people drive at any given
location under good weather and visibility conditions may be
considered as the maximum safe speed for that location.
5. Don’t hate, Decelerate!
Words matter.
■ Reasonable:
– 1 a : being in accordance with
reason a reasonable theory
b : not extreme or excessive
reasonable requests
c : moderate, fair, a reasonable
chance,
a reasonable price
d : inexpensive
– 2 a : having the faculty of
reason.
b : possessing sound judgment a
reasonable person.
■ Prudent:
– characterized by, arising
from, or showing prudence:
such as
a : marked by wisdom or
judiciousness prudent advice
b : shrewd in the
management of practical
affairs prudent investors
c : marked by circumspection
: discreet
d : provident, frugal
6. Don’t Hate, Decelerate!
Who is the 85th percentile tabulated for and does it actually work?
■ The large majority of drivers are
reasonable and prudent.
■ (Drivers) Do not want to have a crash.
■ Desire to reach their destination in the
shortest possible time.
Via:Texas DOT manual
■ 2016Was the DeadliestYear on
American Roads in Nearly a Decade
■ 2016 data shared from the National Safety
Council estimates that as many as 40,000
people died in motor vehicle crashes last
year, a 6% rise from 2015.
■ National HighwayTraffic Safety
Administration released traffic fatality
statistics for the first half of 2016. NHTSA
reported:17,775 deaths on the road in the
first half of the year, up 10.4% from the
same period in 2015.
Makes the assumption, based on old
data, that:
8. Don’t hate, Decelerate!
■ The survey released shows drivers are concerned about safety.
■ 83% of respondents said driving is a safety concern.
■ But that hasn't stopped many of them from speeding, texting, or driving while
impaired by alcohol, prescription medication, or marijuana.
■ Via: http://fortune.com/2017/02/15/traffic-deadliest-year/
9. Why are people prone to speeding?
■ Highway hypnosis (Distracted or
daydreaming).
■ Impatience – just want to get places
quickly.
■ Believe they own the highway and may
do as they please.
■ Enjoy the experience of driving fast.
■ Just doing what everybody else is doing.
■ https://en.wikipedia.org/wiki/Highwa
y_hypnosis
■ http://www.cornellinsurance.ca/Help
Blog/top-10-reasons-drivers-speed/
10. Don’t hate, Decelerate!
Is this reasonable? Is it prudent?
What is driving this new auto culture?
Elon Musk
11. Don’t hate, Decelerate!
The problem with auto ads.
Auto ad
■ Contributes to a sense of entitlement.
■ Creates a false perception that
speeding is cool.
■ Sets false expectations as to traffic. i.e.
open roads.
Reality
■ Roads are public right of ways and
belong to everyone.
■ Speeding is the leading cause of death.
■ Traffic grows more congested and
frustrating.
15. Speeding as an ideology
■ Driver’s who speed based on the false notion that the road is theirs by exclusive right
of operating a motor vehicle.
■ Driver’s who follow the crowd. Monkey see monkey do effect.
■ Driver’s who perceive (falsely) that pedestrians and bicyclists are inferior road users.
16. Don’t hate, Decelerate!
What were up against.
■ Ideology.
■ Example:Car advertisement
■ There's an entire sector of the ad industry that's selling
products, like bath soap - but in a "tough" way.
■ Trucks are significant. For practical reasons, trucks are
associated with a lot of "manly" jobs, especially agriculture
and construction.
■ Truck advertising understands this and pitches trucks as
manly using association with these jobs as the hook.
■ Therefore what's NOT manly? Small cars (Priuses) and
bicyclists.The sales pitch is that you aren't a man if you drive
something smaller
■ People internalize this to the extent truck drivers will run
cyclists and Priuses off the road as a hobby.
■ So you can see that the "be a man = get a truck" sales pitch
rubs off on neighboring or opposing concepts in people's
heads.
17. Now for some good news.
4 surprising ways slowing drivers creates better cities.
■ Safer speed limits don’t necessarily make trips longer.
■ Many people fear that slowing the speed limit in urban areas will dramatically increase
journey time. However, average road speeds in cities are more determined by the
frequency of intersections than speed limits.
■ A safer speed limit can achieve more uniform speeds and reduce dangerous midblock
acceleration, while adding little to overall journey times. Research from Grenoble, France
has shown that a speed limit of 30 kmph (18.64 mph) rather than 50 kmph (31 mph) only
added 18 seconds of travel time between intersections 1 km (.62 miles) apart. Lower
speed limits may even reduce congestion in some cases, as they reduce the likelihood of
bottlenecks.This has been observed in Sao Paulo, where lowering the speed limit on major
arterials reduced congestion by 10 percent during the first month of implementation,
while fatalities also dropped significantly.
18. Fourth UN Global Road SafetyWeek 2017
8-14 May 2017
■ Countries successfully reducing road traffic deaths have done so by prioritizing safety
when managing speed. Among the proven strategies to address speed include:
■ Building or modifying roads to include features that calm traffic
■ Establishing speed limits to the function of each road
■ Enforcing speed limits
■ Installing in-vehicle technologies
■ Raising awareness about the dangers of speeding.
19. Why we need to slow drivers down.
Driver’s visual perception of the road at various speeds.
40 kph = 25 mph 70 kph = 44 mph
21. Raising awareness.
Take the “Don’t Hate, Decelerate!” pledge.
Idea’s
■ Negative.
■ Why speeding is dangerous (lecturing).
■ Increase ticketing.
■ Have a group of people hold up signs
saying “Shame on you for speeding.”
■ Create a website logging speeding
drivers by make, model, and license plate
number.
■ Positive.
■ Educate drivers on how they directly benefit
from lower speeds.
■ Use Strava to record driving speed and submit
for a drawing in a contest.
■ Work withTigard police on a program to
reward drivers who consistently operate at
safe driving speeds.