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obtained before any data was collected, using consent mate- While approaching the crossing location, participants were
rials approved by the IRB at Western Michigan University told which lane of the roundabout they were crossing, which
and NAS (Appendix N). The participants received an honorar- direction traffic would approach from, and whether they
ium and were provided transportation assistance as needed. were crossing from the island or curb. For example: "You are
Participation was strictly voluntary, and participants were crossing the entry lane of Davidson from the curb, with traf-
allowed to withdraw from the experiment at any time or for fic coming from your left [touch left shoulder]. Cross when-
any reason. The honorarium and transportation assistance ever you're ready." Participants were reminded that the exper-
were provided independent of whether a participant com- imenter merely informed them when the trial began, not that
pleted all trials. Sixteen to 18 participants were recruited for it was a safe time to begin crossing. Before beginning trials,
the pretest in each location, with approximately 12 individu- they were told that after the experimenter said "cross when-
als completing both pretest and posttest at each site. ever you're ready," they should identify a safe time to begin
crossing and then cross the street. The experimenter stopped
each participant on the opposite side of the street (or on the
Orientation
island) at the end of that trial. After at least one vehicle had
After consent was obtained, participants were oriented to crossed the crosswalk (or 30 s, approximately, if no vehicles),
the roundabout or CTL by the O&M specialist. Orientation the experimenter guided the participant to the starting point
included using tactile maps; walking around the facility with for the next crossing and began another trial.
the experimenter, who described features; walking across the Participants were allowed to take breaks as needed, and
crosswalk while guided by an experimenter; and then cross- refreshments were provided. After all crossings were completed,
ing independently using the experimental procedure. Partic- each participant completed a short debriefing questionnaire.
ipants were encouraged to ask questions about the layout of
the intersection and crosswalks, the traffic movement, the Participant Questionnaires
pedestrian facilities available, and any other features of inter-
est. During the posttest, orientation included a description After each testing session, each participant completed a
and demonstration of the treatments and their operation. debriefing questionnaire. The questionnaire was intended to
ask the participant about the crossings just completed and to
learn about their confidence in crossing at that location.
Procedure
Questions included, for example:
Participants were instructed to cross whenever they believed
it was appropriate to do so, using the cues that were available · "How would you rate your confidence in your ability to
(traffic in pretest, and combination of traffic and treatment- cross here safely on a scale of 1 to 5, with 1 being not at all
related cues in posttest). Participants crossed a specified num- and 5 very confident?"
ber of times at each site. The number of crossings was deter- · "Would you use this crossing if it was on the most direct
mined through pilot testing at each location to fit within the route to and from work?"
approximately 90 min experimental timeframe and to not
result in inordinate fatigue for participants. Each partici- Other debriefing questions focused on crossing strategies,
pant made six round trips (entry, exit, exit, entry or exit, entry, the perceived difference between entry and exit lanes at round-
entry, exit), or 24 crossings, at the Charlotte, NC, single-lane abouts, the difference of crossing from the curb or the split-
roundabout; 20 round trips or 40 crossings at the CTLs; and ter island, and information about the treatments. Questions
12 round trips, or 48 crossings, at the Golden, CO, sites (four included, for example:
round trips at the single-lane roundabout and four round
trips each at both the two-lane roundabout crosswalks). These · "What cues did you use to decide when to cross?"
sites are described further later in this chapter. A trial was · "Did it matter whether you were crossing to or from the
defined as a crossing of one approach, which could entail one island?"
or two lanes of traffic depending on the site (e.g., single-lane · "Were you using the sound from the strips to help you
or two-lane roundabout). Trials were blocked by crosswalk decide?"
(for sites with multiple test approaches) to save time and to · "Did you think the flashing yellow beacon made a differ-
avoid confusing the participants. The starting location (e.g., ence in driver behavior?"
entry or exit leg at a roundabout) was systematically varied to
control for order effects. Posttesting was conducted at the same While the responses to these survey questions are subjec-
crosswalks as pretesting. tive, they add an important feature to the analysis. The results
For each trial, participants were guided to the middle of are presented in Chapter 5 along with more objective perfor-
the curb ramp and were aligned to face across the crosswalk. mance assessment, such as the average delay time. Appendix G
