Automotive User Interfaces and Interactive Vehicular Applications

Situation-adaptive driver assistance systems for safe lane
change via inferring driver intent
Huiping ZHOU
University of Tsukuba, Japan
1-1-1 Tennodai, Tsukuba, Ibaraki
305-8573, Japan
+81-29-853-5011
zhouhp@css.risk.tsukuba.ac.jp
ABSTRACT
This paper focuses on driver intent inference by investigating
driver glance behavior and driving maneuver, and attempts to
show a general framework to design a situation-adaptive driver
assistance system for avoiding a crash or an incident. The results
show that inferring driver intent via monitoring driver glance
behavior is not only to comprehend driver intent, but also
important to detect if the driving performance is safe. The study
revealed how to apply the intent inference for providing an
appropriate support at a proper time point, which is expected to
improve driver’s acceptance and driving safety.
Keywords
Situation-adaptive automation, driver intent, safety, glance
behavior
1. INTRODUCTION
National Highway Traffic Safety Administration (NHTSA) has
shown that approximately 25% of crashes were attributed to
driver distraction [1]. Furthermore, many transportation
researchers revealed that drivers’ recognition failure accounted for
65-75% of the lane changing/merging crashes, in which drivers
failed to be aware of traffic environment around, or initiated
changing lanes without recognizing a vehicle driving in a blind
spot [2]. For the recent decades, several intelligent driver
assistance systems have been developed for preventing such a
distraction-related crash. Those functions can be classified into
different types: (1) caution type support functions for enhancing
driver’s situation awareness [3], e.g., Blind Spot Information
System (BLIS), (2) warning type support functions for aiding
driver’s decision making, e.g., Lane Change/Merge Warning
systems, (3) and action type of support function for assisting
driver’s operation.
As many types of advanced drive assistance systems are
developed, the selection of an appropriate system is becoming an
important issue to be addressed [4]. Inagaki points out that it is
necessary to take “who should do what and when” into account
[5]. Thus, it is claimed that it is necessary to develop a situation-
Copyright held by Huiping ZHOU, Makoto ITOH, Toshiyuki INAGAKI.
AutomotiveUI’11, November 29-December2, 2011, Salzburg, Austria.
Adjunct Proceedings.
Makoto ITOH
University of Tsukuba, Japan
1-1-1 Tennodai, Tsukuba, Ibaraki
305-8573, Japan
+81-29-853-5502
itoh@risk.tsukuba.ac.jp
- 39 -
Toshiyuki INAGAKI
University of Tsukuba, Japan
1-1-1 Tennodai, Tsukuba, Ibaraki
305-8573, Japan
+81-29-853-5537
inagaki@risk.tsukuba.ac.jp
adaptive automation, which trades the authority of control in a
dynamic manner. That is to comprehension driver’s intent
creation before an initiation of driver’s maneuver.
The purpose of this study is to investigate how to develop a
situation-adaptive driver assistance system for changing lanes
based on an inference of driver intent.
2. Driver’s lane-change intent
2.1 Driver glance behavior
Zhou, Itoh, and Inagaki [6] investigated driver’s glance behavior
on the side-view mirror for preparing lane-change. The result
showed that the glance behavior increased significantly once a
driver created an intent to change lanes. Based on this finding, an
algorithm for inferring the driver lane change intent was
developed. In the algorithm, four levels of driver lane change
intent were distinguished:
� EXTREMELY LOW: A driver has not recognized a slower
lead vehicle or has not decided to pass the lead at all;
� LOW: He/she has decided to pass the lead vehicle;
� MIDDLE: He/she decided to pass the lead vehicle, but not
determine to change lanes yet,
� HIGH: He/she determined to change lanes once the traffic
conditions allow an implementation,
Based on the frequency, say N, of driver glance behavior to look
at the side-view mirror within the last 12 seconds, the driver lane
change intent was regarded as LOW when 0 < N � 1, as MIDDLE
when 1 < N � 3 and HIGH when N � 4.
2.2 Distracted driver’s lane-changing intent
Zhou et al. [7] also investigated driver’s glance behavior under
cognitively distracted situations. Driver glance behaviors were
collected and analyzed under the two conditions: driving without
secondary cognitive task and driving with a secondary cognitive
task. As the distracting secondary task, a secondary task of
“Telling a story” task was given to the participants. During
driving, drivers were asked to make a short story with using the
four key-words from a speaker connected with a PC, and to tell
the story for at least 50 seconds during preparation of the lane
change. The result showed significant decrease of the glance
behavior frequency under the condition of driving with the
secondary task. Based on the comparison of driver’s glance
behavior under the two conditions, Zhou, et al. claimed that there
existed two types of inappropriate lane-changing intent creation
under the distracted-driving condition. One is the delay in intent
creation (Figure 1(a)), where the lane change was done lately, and