Using Czech TCT to Assess Safety Impact of Deceleration Lane at Thai U-turns

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

Using Czech TCT to Assess Safety Impact of Deceleration Lane at Thai U-turns

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

Integration of the component of financial statement in highway maintenance planning

Highway agencies attempt to apply efficient accounting systems to help improve the transparency of their budget allocation and their overall performance. The accrual accounting system has been adopted to substitute the cash accounting system by many central governments around the world. The system reports transactions of economic value changes rather than when cash movements are made. The asset value and its depreciation determined by the accrual accounting system illustrate the total amount of economic value owned by an agency and the consumption of the future economic benefits for an asset. The age-based depreciation approach, which is a traditional approach, is applied to determine the depreciation of an asset based on the defined useful life and the straight-line depreciation method. The advantage of this approach is its simplicity and its ability to support the long-term asset management system. The condition-based depreciation is recommended as an alternative approach since the actual condition of an asset can reflect its depreciation. The depreciation of an asset based on the condition-based approach is suitable for single-year maintenance planning since the executives cannot estimate the required budget for replacing or preserving of an asset in the long-term period. This research focuses on developing the new depreciation approach by integrating the age-based and the condition-based depreciation approaches in order to strategically plan long-term highway maintenance and to enable the actual condition of an asset to be reflected.Asset management, accountability, maintenance, highway,

Returning to Public Transportation in Transitioning Out of COVID-19: Effects of Passenger Satisfaction on Frequency of Use of Rail Transport

As travel restrictions ease amid the COVID-19 pandemic, a revival of traffic congestion is observed caused by the increased use of private vehicles. To help alleviate this, return to public transport use is encouraged. Given the positive relationship between passenger satisfaction and their recurrent use of public transit, it is then recommended to improve the service quality offered by these systems. This paper illustrates the use of a combination of principal component analysis and ordinal logistic regression in determining how satisfaction with rail transport service quality affects passengers' usage frequency with Bangkok's mass rapid transit system as a case study. The results show that satisfaction with ticket sales, station facilities, station staff, public relations, and rolling stock significantly affect passengers' recurrent use of the rail transport system. It is also determined that among these indicators, the station facilities, rolling stock, and station staff are found to contribute greatly to the marginal effects on the probability of observing more frequent use compared to less frequent use. It is then recommended that these factors be prioritized and further improved to produce higher levels of passenger satisfaction, and consequently, increased ridership of the rail transport system. The findings of this study can also be beneficial for public agencies and rail transport operators with regard to policy and decision making amid and in the transition out of the COVID-19 pandemic