Everyday Cycling in Urban Environments: Understanding Behaviors and Constraints in Space-Time - Computational Approaches for Urban Environments - page 190

8.4.2 The Concept of Corridor Space Analysis

Corridor-based analysis has been used in several transport-related studies: the
location of high crash concentrations within the context of bridging the gap in
highway safety analyses (Smith et al. 2001 ), prehistoric cultural activity (Hazell and
Brodie 2012 ), as well as modeling and identification of species migration corridors
(Hargrove and Westervelt 2012 ). This section discusses the concept of corridor
space analysis (CSA) for exploring movement patterns as well as some merits and
potential drawbacks of such an approach for data analysis.

8.4.2.1 Corridor Space Analysis for Exploring Movement Patterns

Data collection, alone, is not enough for analysis; matching GPS-tracked data to
other spatial datasets is also necessary albeit a difficult task. It is in this difficulty
that the concept of corridor space is introduced to address how spatial analysis
could be done when collected data and available datasets do not fit properly due to
data inaccuracy issues. The corridor space is defined as a buffer zone around cycle
lanes/paths used for detecting cycle trips/cycle trip sections/other available cycle
infrastructure. The analysis associated with the use of corridor space in determining
an area of interest and further inquiry therein is what is termed the corridor space
analysis here. A cycle trip is defined here as any journey by an adult cyclist bounded
by origin and destination and identifiable in both a travel diary by purpose(s) and
GPS data by geometry. The concept is used to distinguish cycle trips off , on ,or near
the official cycle network in the study area.
For a given buffer distance a , half of that would equal b asshowninFig. 8.5 .
Mathematically, let us assume B D (B 1 ,B 2 , :::,B n )whereB 1 is a trip or trip
segment within the blue region (i.e., the on region) as shown in Fig. 8.5 . Similarly,
G D (G 1 ,G 2 , :::,G n )whereG 1 is a trip or trip segment within the green region (i.e.,
the near region), whereas R D (R 1 ,R 2 , :::,R n )whereR 1 is a trip or trip segment
within the off region. The total distances for each region (i.e., BT, RT, and GT) could
be represented in Eqs. ( 8.1 ), ( 8.2 ), and ( 8.3 ), such that the total distance for all cycle
trips should approximate BT C RT C GT and that BT ¤ GT.

n

X

BT D B k (8.1)

kD0

n

X

RT D R k (8.2)

kD0

X

n

GT D G k (8.3)

kD0