Research Trends and Results

Bicycle traveling space mixing bicycles andautomobiles
KIMURA Yasushi, Research Engineer
OHASHI Sachiko, Senior Researcher (Dr. Eng.)ONIZUKA Daisuke, Guest Research Engineer
YABU Masayuki, HeadAdvance Road Design and Safety Division, Road Department(Key words) Bicycle traveling space, mixed traffic lane, design
1. Introduction
Since November 2012, when the Ministry of Land,
Infrastructure, Transport and Tourism and theNational Police Agency released the Guideline to theCreation of Safe and Pleasant Bicycle Utilization
Environments1) (below called, “the Guideline”), thecreation of bicycle traveling spaces has been
beginning in earnest in throughout Japan.
Under these circumstances, the NILIM has analyzed
the effectiveness and problems revealed byfact-finding surveys of the use of bicycle travelingspace which has actually been created, and this reportintroduces part of these findings: research on mixed
vehicle lanes (a form in which bicycles andautomobiles share a traffic lane), which is one form ofbicycle traveling space.
2. Bicycle traveling space called a mixed vehicle
lane
Past provision of bicycle traveling space has often
been carried out by installing bicycle paths, which
physically separate bicycles and automobiles, orbicycle lanes, which are separated visually, on roads
with relatively wide extra space. But looking at overallroads shows that on many roads, heavy bicycle traffic
requires the provision of bicycle traveling space where
there is no extra road width. Regarding such roads, theGuideline recommends that because of automobile
traveling speed and automobile traffic volume etc.,
even on a road where structural or visual separation isdesirable, if restrictions on width makes the provisionof such separations difficult, a mixed vehicle lane canbe studied as a temporary form. But, few mixed
vehicle lanes have been established, and it cannot be
said that our knowledge about the traffic behavior ofbicycles and automobiles is adequate. And methods ofplacing road surface indicators showing the locationsof mixed vehicle lanes for use by bicycles have not yet
been specifically established.
3. Description of the research
The NILIM is now conducting the following studies
at actual locations of mixed vehicle lanes in order toPhoto. Example of a Mixed Traffic Laneclarify the traffic behavior, safety, and comfort inmixed vehicle lane type bicycle traveling space.
(1) Analysis of bicycle/automobile traffic behavior
Change of bicycle traveling line (bicycle pedestrianpaths or traffic lanes) after provision, behavior of
bicycles and automobiles when close together or when
an automobile passes a bicycle, and whether or not
conflict occurs were surveyed and traffic behavior wasorganized to analyze safety.
(2) Study based on a traffic micro-simulation
Based on the traffic behavior so obtained, a traffic
micro-simulation capable of reproducing behavior of
an individual bicycle or automobile was done
reproducing the state of traffic on a mixed vehicle lane,
and at the same time, sensitivity analysis was
performed based on the change of bicycle andautomobile traffic volumes to clarify problems which
could occur according to traffic conditions.
(3) Survey of consciousness of users
A questionnaire survey of users was performed to
examine mutual consciousness of bicycle andautomobile users regarding travel on mixed vehicle
lanes, and the visibility and comprehensibility of roadsurface indicators, to analyze the effectiveness ofproviding mixed vehicle lanes and problems theycause.

Research Trends and Results
4. Future activities
Results of research on mixed vehicle lanes will be
regularly released by announcing reports of theseresults. And we will continue to accumulate andorganize knowledge about the provision of bicycle
traveling space, and publish this information as
technical documents to be used to support theprovision of bicycle traveling space now underway invarious parts of Japan