148｜PracticeSignificant reduction of cycle length via a
two-stage crossing system
1. Background and goals
The cycle lengths (1) of signals at large
intersections in Japan are much longer••

than those in Europe. This can irritatepedestrians, who must wait a long time
for crossing signals to change at intersections. In addition to intersection traffic
demand, the amount of time that pedestrians require to cross intersections has alarge effect on determining cycle lengths.
One method to reduce cycle lengths currently attracting attention is the introduction of two-stage crossings, where acentral island in the middle of a crosswalk is established and pedestrian crossing signals allow crossing independently
to either side of the island (Fig. 1, 2).
In this project, we performed a pilot
survey for reducing cycle lengths throughthe introduction of two-stage crossings.
We first accumulated research throughon-site investigations and simulation
analysis. Based on this, and with the support of road and traffic administrators,•

A central island is established in the crossing
A pedestrian crossing signal is added tothe central island
A design and control method where pedestrians
can wait (as opposed to “are made to wait”) in

the central island
Slower-walking pedestrians can wait
safely in the central island• Allows signal cycle length reduction• Pedestrian signal displays can be divided•

at the central island

Figure 1. What is a two-stage crossing?

Two-stage通常
display division

In the two-stage crossing method, a green signal is displayed in regions where cars turning right cannot passThis increases the space and time available for pedestrians in crosswalks,
increasing pedestrian passage rates2Figure 2. Two-stage crossings and signal display division

we installed two-stage crossings at the Kasumigaseki 2-chome intersection in downtown Tokyo, Japan.

Project Leader: Hitoshi Ieda
Professor, Graduate School of Engineering, The University of Tokyo / National Graduate Institute for Policy Studies(1) Signal cycle length: The time for the light on a traffic signal to cycle through green, yellow, red, and back to green. At large intersections in Japan, the signal cycle length is normally from 120 to 150 seconds.

Significant reduction of cycle length via a two-stage crossing system｜149

2. Research content
In this project we (1) planned and implemented a public
relations strategy, (2) performed a pilot survey and investigation, and (3) verified the effects of the experiment.
2-1. Planning and implementation of a public
relations strategy
At first glance it might seem that two-stage crossings areeven more inconvenient for pedestrians because the central

3Figure 3. The public relations logo
構内の３箇所に説明パネルを展示

island increases the number of times they must wait for signals, among other reasons. We therefore performed various
strategic public relations activities so that users would better
understand the intent of two-stage crossings.
Specifically, we created the “Easy Crossing Project
KASUMIGA SEKI” campaign (Fig. 3), and (1) installed
explanatory panels in the Kasumigaseki subway station (Fig.
4), (2) distributed leaflets to government agencies, publicoffices, and pedestrians in the area, (3) created a website foranswering questions and collecting opinions, and (4) advertised to the mailing lists of various organizations.
2-2. Implementation of the pilot survey
and investigation
The pilot survey was performed starting on 13January 2009 from 10:00 to 15:00 on weekdays
for one month. To ensure complete safety, we stationed a traffic guide in the central island whohelped guide pedestrians (Fig. 5).
We began the experiment using a cycle
length of 75 seconds (approximately one-half thenormal time of 140 seconds), but as it became

Figure 4. Explanatory panels weredisplayed at three locations in the station

Ministry ofFinance

Ministry ofForeign Affairs

Ministry ofAgriculture,
Forestry andFisheries

Ministry of Economy,
Trade and Industry

Before theexperimentDuring theexperiment

Divided signals

apparent that this caused pedestrians crossing in
the counterclockwise (CCW) direction to rush,
we extended the cycle length to 100 seconds from
9 February. Note that for the duration of theexperiment, the cycle lengths at surrounding
intersections were set to 150 seconds.
We conducted the following two investigations to measure the effects of the experiment:

Placement of traffic guides Utilizing the central island

Figure 5. The pilot survey

5150｜Practice(1) Video survey: We videotaped the crossing, and from this we measured factors such as pedestrian wait times, walking speed, how much pedestrians ignored signals, and situations when pedestrians and automobiles came into conflict.
(2) Questionnaire survey: we conducted a questionnaire survey to determine pedestrian psychology at crossings and degree of acceptance of the new crossing method.
2-3. Verification of the effect(1) Results of the video survey
Video analysis of pedestrian
behavior yielded the following
results (Table 1). Note that in theanalysis we weighted the spacing
between arrival times of individual pedestrians, and calculated
each index as a normalized uniform arrival distribution withconstant density.

Table 1. Analysis results (comparison with a 140-second cycle length)
Measurement item

Two-stage crossing Two-stage crossing(75 seconds)(100 seconds)(1) Average pedestrian wait time

CW: 53% decrease
CCW: 18% decrease

CW: 54% decrease
CCW: 6% decrease(2) Average walking speed

CW:
6% increase
CCW: 26% increase

CW:
CCW:

(3) Pedestrians in crossing after signal
changes to red

CW:
3% decrease
CCW: 61% increase

CW:8% decrease
CCW: 30% increase(3)’ 95th percentile walking time after
signal changes to red

CW: 67% decrease
CCW: 20% increase

CW: 74% decrease
CCW: 12% decrease(4) Pedestrians in central waiting island

CW:0%
CCW: 34%

CW:0%
CCW: 28%

3% increase
9% increase(a) Changes in pedestrian wait times
We found that average pedestrian wait times decreased in all scenarios. Specifically, with a cycle lengthof 75 seconds (C75) the wait time for pedestrians crossing in the clockwise direction (CW) wasdecreased by 53% and that for pedestrians crossing in the CCW direction was decreased by 18%. With acycle length of 100 seconds (C100), the CW decrease was 54% and the CCW decrease was 6%.
(b) Changes in walking speed
We next examined average pedestrian walking speed and found that with C75 there was a 6% CW
increase and a particularly high 26% CCW increase. With C100, there was a significantly smaller
increase in walking speed in both directions of just 3% CW and 9% CCW.
(c) Changes in the ratio of pedestrians remaining in the crosswalk and in pedestrian walking time aftersignal change
We also compared the ratio of pedestrians remaining in the crosswalk when the signal became red,and found that while there was a 3% CW decrease with C75, there was a very large 61% CCW
increase. The CCW increase was lowered to 30% with C100. This is still not a low number, but when
we compare 95th percentile values of walking time after signal change for pedestrians remaining inthe crosswalk, we found that although with C75 there was a 20% CCW increase, with C100 there wasa 12% CCW decrease. This indicates that with C100 pedestrians are clearing out of the crosswalk
faster than with C75. When we interviewed the traffic guides regarding this, they reported that many

Significant reduction of cycle length via a two-stage crossing system｜151

CCW-walking pedestrians ignored signals when the cycle length was 75 seconds, but that this was not
a problem at 100 seconds.
(2) Questionnaire survey results
Responses to the questions “Were you able to cross with less waiting time than at other intersections?”
and “Were you able to cross without hurrying?” showed trends similar to those found as a result of video
analysis. Responses to the question “Do you think that crosswalks with a central waiting island and separate crossing signals like those used in this experiment should be applied to various other intersections?” were around 70% positive for pedestrians crossing in each direction, indicating a high level ofpedestrian acceptance of two-stage crossings. However, slightly less than 40% of respondents reported
difficulty understanding how to cross the two-stage crossings, indicating that this is a problem that must
be addressed.

3. Conclusions
Results of the analysis of the pilot survey performed in this project indicate that cycle length reduction
via two-stage crossings is an extremely effective measure for reducing automobile and pedestrian wait
times and irritation. Considering that nearly 70% of pedestrians had positive feelings toward this experiment, we believe that there is a high probability that the introduction of two-stage crossings in Japan
will be accepted to reduce cycle times. We note, however, that negative opinions related to pedestrian
confusion were expressed regarding the new crossings. Some pedestrians would try to cross them in theusual manner, not noticing the change in signals.
In the future, it will be necessary to accumulate experience at a variety of intersections to discovermethods by which two-stage crossings can be better understood, such as by changing crossing structure,adjusting the position and size of signals, changing how remaining time and wait times are displayed, orproviding road lighting and voice guidance.

4. Future outlook
Since the implementation of this project, both road and traffic administrators have gained an understanding of the effectiveness of two-stage crossings, and the implementation of these systems will beconsidered at some locations. However, the true effect of cycle length reduction via the introduction oftwo-stage crossings will only be seen after the verification of network effects through their introduction
at multiple locations. It will therefore be essential in the future to select locations where this method canbe applied as a network, and to perform trial implementation in those areas. As we head toward theTokyo Olympic Games in 2020, we must ensure that road intersections in Japan do not pose an international embarrassment, and that we continue to make changes for their increasingly comfortable use byboth pedestrians and automobiles.