6.2 Identification of Potential Black Spot Locations
By utilizing an integration of Hiyari-Hatto, a traffic psychological concept with public
participation and cognitive map approach, it explicitly entails the significant results in terms
of practical identification on the potential black spot locations in Soi Pavana and Soi
Chokchai 4 communities. The possibility has come to realize as expected that the process by
which allows local people to participate in the questionnaire survey for expressing or sharing
the information and experiences of their potential road traffic accidents in their community is
pragmatically adoptable. Results from the survey indicated that 111 respondents have seen
and thought the potential risk of accidents while 17 of them have had experienced a moment
of potential accident. Whereas 37 respondents had seen the real scene of traffic accidents, 18
respondents have had experienced the traffic accident happened to them.
There are total numbers of 59 hazardous locations identified by the respondents. Some are
identified as potential hazardous/potential black spots and some are existing black spots and
some are identified as both potential hazardous and existing black spots, see Table 1. It is
unfortunate that there have never been any record on the exact location of the accident scenes
even at neither the police stations nor the hospitals. Even if there is such black spot data, it is
quite limited and proprietary which has never been shared to public. Hence, there is no
existing black spot data for comparison with the findings of these specific 59 hazardous spots.
This is a fundamental problem of lacking mutual cooperation, inefficient data collection and
data recording processes led to unreliable of the data in developing country including
Thailand.
According to the survey, despite only less than 20 percent of respondents could draw
accidental location themselves and the rests were being assisted, it is amazing that they could
illustrate the incidence exactly as happened. The results of cognitive map approach adoption
revealed magnificent data that are used for specifically identifying the location of accident
occurrence and the road configuration /shape of each black spot as indicated in Table 1.
Figure 6 and 7 illustrated examples of drawing cognitive map done by respondents living in
the study area of the T-junction of Yeak Krongprab-Wat Ladprao and Soi Patanatidin
intersection (Bunrudee Kindergarden School) in comparison with the real picturesque
locations. Figure 8 demonstrates the comparative and collective potential black spot and
existing black spot locations in GIS format according to the point of view of Soi Panava and
Soi Chokchai 4 local communities. Figure 9 indicates the name of the overall potential and
existing black spot locations and Figure 10 represents the real map route of Soi Panava and
Soi Chokchai 4 Roads for comparison. Unfortunately, it is quite impossible to indicate cause
of accidents on the GIS map.
The places where the traffic accidents most occurred are at the Y-junction of Yeak Pavana-
Wat Ladprao, the T-junction of Yaek Krongprab-Wat Ladprao, and at Soi Patanatidin
intersection (Bunrudee Kindergarden School). The contributory factors of the accidents were
mostly human error such as driving recklessly, no signaling prior to turn or stop, and followed
too closely. As observed at the sites and as indicated by the respondents, the 2 Y-junction and
T-junction of Yeak Pavana-Wat Ladprao and Yaek Krongprab-Wat Ladprao (see, Figure 6)
are already signalized which controlled by the traffic police but has been off and is used for
only on a special occasion. The road users who drive or use these routes may have to
challenge with the first come first get the road basis. However, some respondents claimed that
these signalized sections sometimes caused more traffic than other non-signalized intersection.
Having signalized at intersection sometimes interferes with the traffic flow resulting in
delaying travel time but if allows the traffic control signal work automatically and
systematically this will bring the traffic situation to equilibrium and hence reducing the traffic
accidents consequently. As for the non-signalized Soi Patanatidin intersection is now awaited
for the traffic signal installation which expected to be completed by the end of this year
(2004) (see Figure 7).
Notwithstanding some major map reading and drawing problems, through utilizing direct
public participation approach with traffic psychological method of Hiyari-Hatto, this research could elicit the information pertaining to the accident collision and causation from the
respondents which is a significant breakthrough in this identification of potential black spot
study. The following section below describes the correlation between potential and existed
accident attributes and its causations.