penn potomac independent audit - karen lin

Pedestrian Behavior &

Artifact Audit

June 2013

An Independent Review for the

Penn-Potomac Avenue SE Pedestrian Safety Study

Karen T. LinHuman Factors & Public Safety Consultant

[email protected] | +1 435 565 4544 | karentl.com

INTRODUCTION

My name is Karen T. Lin and I’m an independent human

factors consultant. As a new DC area resident who walks

around the Penn-Potomac neighborhood, I am volunteering

my services pro bono for the benefit of the Penn-Potomac

Avenue SE Intersection Pedestrian Safety Study and for the

benefit of the public for which it affects.

I’ve conducted a high-level behavior audit of the immediate

intersection and would like to share my initial findings and

human-centered design recommendations with any and all

parties committed to the pedestrian safety study.

2June 2013 This is an independent audit © 2013 Karen T. Lin

APPROACH

Human factors is the field of study concerned with the

human-centered design of a system, service or product to

reduce error and other undesired outcomes while

optimizing for desired outcomes in human and system

performance.

In this This is an independent audit, I visited the Penn-

Potomac intersection to observe pedestrian behaviors and

record artifacts (observable signs of human or system

activity) and identify trends or patterns that are creating

undesirable conditions for pedestrian safety today.


Walking paths between Metro and major bus stop

B

Paths via marked pedestrian walkways

Paths via shortest walkable distance

Barriers to walk around (fences, bus stop stands)

M

M B

4June 2013 This is an This is an independent audit © 2013 Karen T. Lin

A closer look at the “spread” of the foot paths

The “spread” suggests pedestrians may be crossing through from different angles

and/or treading the sidelines while waiting to cross traffic.

5June 2013 This is an This is an independent audit © 2013 Karen T. Lin

PHOTO OF FOOT PATHS & SPREADS: View from main bus stop to the Metro station. Again, the

“spreads” indicate pedestrians may be treading along the curblines and/or jaywalking diagonally to

cross the streets, presumable to weave between cars & buses.


The Southwest Corner = More foot paths and problems

Seen and unseen footpaths School crossing guard stationMon-Fri 7:00-9:00am & Mon-Thu 2:00-4:00pm, Fri 12:00-2:00pm

Triangular median


PHOTOS: Views of the other foot spreads and paths. Notice there are NO physical

barriers to prevent pedestrian from taking shortcuts into traffic.

Foot spread outside the Penn

Ave outbound bus stop

Foot path/spread at Penn-

Potomac going southbound


PHOTO: View of the triangle median and its pedestrian walkway. Notice how the “stop

for pedestrians” sign is facing at an angle AWAY FROM cars driving into the walkway…


…and instead, the sign faces pedestrians on the foot path. This may give pedestrians a

false sense of security to see this sign while the drivers don’t see it.


OPPOSITE VIEW: A Garda truck parks here often, blocking the path and view of cars

turning right from Penn Ave. (Note lack of road markings to indicate proper use of lanes.)


OTHER ISSUES: Who is this walk sign for?

This walk

signal is

missing a

corresponding

crosswalk.

All other walk

signals in this

area have

corresponding

crosswalks.

Side note:

Again, it’s

unclear if

there are one

or two lanes.

Cars squeeze

in to not get

stuck or

backed up on

the turns.


OTHER ISSUES: Misleading “allowance” of shortcuts

The wrought-iron fence (right) ends in a “misleading” way. People with wheelchairs & strollers

cross over to the Metro station, only to find no ramp or walkway. (I witnessed a man in a powered

wheelchair attempt to navigate onto the road WITH traffic to get around the curb.)13June 2013 This is an independent audit © 2013 Karen T. Lin

ADDITIONAL CONSIDERATIONS

Pedestrian STOP signs should face oncoming traffic in the

order of the driver’s viewing angle. Especially in cases of

curving roads, pedestrian stop signs must precede the

walkway in order of the driver’s attention events.


1. Driver’s viewing angle

changes with the road, sweeping

RIGHT TO LEFT in this example.

2. Therefore, place the sign to the

right of the walkway, facing the angle

at a safe distance in before driver sees

and enters the walkway

3. For a road bending right, the

driver’s view sweeps from LEFT TO

RIGHT, so the sign should be placed

on the left of the walkway.


Use pedestrian barriers to discourage accidents. In cases

where jaywalking pedestrians must check for car traffic

over their shoulder and from multiple directions, use

barriers (no more than 4 feet tall) along medians to

discourage the behavior.


car traffic

car traffic

foot traffic to

prevent with

barriers


Use road markings to clarify usage. Where roads are

physically wide enough for two lanes but are unmarked, it

creates driver confusion and ambiguity on appropriate

usage – and adds risk in high traffic hours.


Example 1: Dotted white line to

indicate two lanes.

Example 2: Straight white lines as

margins for a single lane of traffic.

ADDITIONAL NOTES

• School crossing guard mentioned several other safety

concerns regarding parents with cars dropping children

off in unsafe zones, students themselves not using her

crosswalk (or any crosswalks), cars that drive by too

quickly, and needing more crossing guards (as she is the

only one).

• The wrought-iron fence is mostly camouflaged by

bushes. I witnessed at least 2 people attempt to cross

between the bushes only to realize they would have to

walk around it. Bushes/plants should be maintained at a

shorter height to discourage shortcut attempts.


THANK YOU

I’m happy to assist anytime with questions, concerns,

and/or if I may be of any additional help.

Karen T. Lin

Human Factors & Public Safety Consultant

[email protected] | +1 435 565 4544 | karentl.com


penn potomac independent audit - karen lin

Technology

independent audit

independent review

pedestrian barriers

pedestrian behaviors

highlevel behavior audit

pedestrians sign

penn potomac intersection

foot spreads