TY  - JOUR
A1  - Meel, Inder P.
A1  - Satirasetthavee, Dussadee
A1  - Kanitpong, Kunnawee
A1  - Taneerananon, Pichai
T1  - Using Czech TCT to Assess Safety Impact of Deceleration Lane at Thai  U-turns
JF  - ENGINEERING JOURNAL-THAILAND
N2  - Purpose of this study is to evaluate safety impact of the deceleration lane at the Upstream Zone of at-grade U-turns on 4-lane divided Thai highways. A substantial speed reduction is required by vehicles for diverging and making U-turn, and the deceleration lanes are provided for this purpose. These lanes are also providing a storage space for the U-turning vehicles to avoid unnecessary blockage of through lanes and reduce the potential of rear-end collisions. The safety at the U-turn is greatly influenced by the proper or improper use of the deceleration lanes. Subject to their length, full or partial speed adjustment can occur within the deceleration lane also the road users’ behavior is influenced. To assess the safety impact, the four groups of U-turns with the varying length of deceleration lanes were identified. Owing to limitation of availability and reliability of road crash data in Thailand, widely accepted Traffic Conflict Technique (TCT) was used as an alternative and proactive methodology. The U-turns’ geometric data, traffic conflicts and volume data were recorded in the field at 8 locations, 8 hours per location. Severity Conflict Rate (SCR) was assessed by applying a weighing factor (based on the severity grades according to the Czech TCT) to the observed conflicts related to the conflicting traffic volumes. A comparative higher value of SCR represents a lower level of safety. According to the results, increase in the functional length of the deceleration lane yields a lower value of SCR and a higher level of the road safety.
KW  - Verkehrssicherheit
KW  - Highway
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170406-31097
SP  - 121
EP  - 135
ER  - 
TY  - JOUR
A1  - Meel, Inder P.
A1  - Brannolte, Ulrich
A1  - Satirasetthavee, Dussadee
A1  - Kanitpong, Kunnawee
T1  - Safety impact of application of auxiliary lanes at downstream locations of Thai U-turns
JF  - IATSS Research
N2  - To assess the safety impact of auxiliary lanes at downstream locations of U-turns, the Traffic Conflict Technique was used. On the basis of the installed components at those locations, four types of U-turns were identified: those without any auxiliary lane, those with an acceleration lane, those with outer widening, and those with both an acceleration lane and outer widening. The available crash data is unreliable, therefore to assess the level of road safety, Conflict Indexes were formulated to put more emphasis on severe crashes than on slight ones by using two types of weighting coefficients. The first coefficient was based on the subjective assessment of the seriousness of the conflict situation and the second was based on the relative speed and angle between conflicting streams. A comparatively higher Conflict Index value represents a lower level of road safety. According to the results, a lower level of road safety occurs if two components apply or if a location is without any auxiliary lane. The highest level of road safety occurs if the layout includes only a single component, either an acceleration lane or outer widening.
KW  - Verkehrssicherheit
KW  - Beschleunigungsstreifen
KW  - Auxiliary lane; Conflict Indexes; Road safety; Traffic Conflict Technique; U-turn
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170401-31016
UR  - http://www.sciencedirect.com/science/article/pii/S0386111216300140
ER  -