●A Case of Utilizing Results

A Road Traffic Survey Platform
Application of “Reference Road Segments andReference Intersections”
Traffic Engineering Division, Road Department
MATSUMOTO Shunsuke (Research Engineer), HASHIMOTO Hiroyoshi (Research Engineer),MIZUKI Tomohide (Guest Research Engineer), MONMA Toshiyuki (Senior Researcher),
UESAKA Katsumi (Head)(Keywords) Traffic survey, digital road map, database
1. Introduction
NILIM has developed a “Standard for Traffic
Survey Unit” as a platform for traffic surveys. The
standard was introduced into the FY2010 Road Traffic
Census and is expected to have broad application inthe future. Within the standard, reference roadsegments (hereafter “reference segments”) areestablished as the smallest survey units for varioussurveys. They are divided at the points shown in
Table 1 to allow easy inter-application, analysis, andaggregation of survey results.

Road conditions survey

Table corresponding to
区間対応テーブル
segment

Reference road

交通調査基本区間
segment

道路状況調査単位区間
segmentRoad
conditions data
道路状況データ
Traffic
volume survey segment
交通量調査単位区間
Traffic
volume data
交通量データ
Travel speed survey segment
旅行速度調査単位区間
Travel speed data
旅行速度データ等

Referenceintersection
基本交差点DRMsegment
DRM区間
Probe data, etc.
プローブデータ等
2005 census segment
H17センサス区間
Resultsof 2005 census
H17センサス結果
Roadsegment ID method
道路の区間ID方式

Routeanalysis
路線分析Intersection

交差点分析
analysis

Network analysis
ネットワーク分析

Othersegments
その他区間
Various data
各種データ

Table 1: Reference road segment division points
Division point
1) Point of intersect withother arterial road2) Point of access to major
facility3) Point of change in roadmanager jurisdiction4) Start point of expressway

5) Point of intersect withmunicipal boundary

PurposeMinimum unit suitable forascertaining traffic volume,
deceleration, and traffic service
Consideration of individual
handling of zones withsignificant differences in traffic
conditions
Consideration of aggregation
with road manager units
Consideration of differences intraffic characteristics andaggregation of expressway data
only
Consideration of aggregation bymunicipality

2. Analysis by route, intersection, and network
Analysis of individual routes and municipalities canbe performed easily by using route attributes in thereference segment.
Moreover, analysis at theindividual intersection and network level are also
possible by using reference intersection data that areautomatically generated using intersecting roadconnection information established for the start andend points of the reference segment (Figure 1).

Figure 1. Analysis at the route, intersection, andnetwork levels
3. Application in congestion analysis at theintersection level
Using reference intersection data, it is possible toconduct, for example, evaluations by aggregatingcongestion-caused losses in all directions fromintersections that tend to be traffic bottlenecks.
Figure 2 shows the results of a calculation of lost time
due to congestion at specific intersections in the Kantoarea.

Time lost due to congestion at reference
intersections (2010 Road Traffic Census)

小Low

大High

Figure 2. Congestion-caused time loss
(intersection level)
Figure 3 shows calculated lost time for eachintersection on National Route 6 in Ibaraki Prefecture.
It can be seen that intersections having large lost times
compared to surrounding intersections largely matchwith major congestion points.

●A Case of Utilizing Results

Fukuoka Pref. border

Okita Bridge

Kasamatsu – Ishinazaka

Mito City(Nat. Rte. 50)

Chiyoda-Ishioka
Interchange

NakanukiIntersection

Vicinity of Ushiku
StationUnderNakamura
overpass

Chiba Pref. border

Lost time: 1,000
person hours/month
損失時間：単位千人時間/月

大北橋

0

福島県境

1050

森山町～田尻町20号）

30

千代田石岡 IC
中貫交差点

40

牛久駅周辺

50

Major
congestion point
主要渋滞ポイント
中村陸橋下

60

千葉県境

70

笠松～石名坂80

水戸市（国道90

Moriyama-cho - Tajiri-cho

損失時間（茨城県国道6号2009年10月）
Lost time (Nat. Rte. 6, Ibaraki Prefecture, October 2009)100

Distance from the Chiba prefectural border
千葉県境からの距離

Figure 3. Congestion-caused time loss in Ibaraki
Prefecture (intersection level)
4. Division of roles in data updates
We will update traffic survey reference roadsegments each fiscal year and reflect them on thelatest road network. To ensure work efficiency,
regional development bureaus will update reference
segments and NILIM will use the updated data they
supply to automatically update reference intersections
throughout Japan.