Category : Systems

Risk-based optimization of rail defect inspection frequency for petroleum crude oil transportation

Liu, X. and C.T. Dick. 2019. Risk-based optimization of rail defect inspection frequency for petroleum crude oil transportation. Transportation Research Record: Journal of the Transportation Research Board. 2672 (1S): 27-35. doi:10.3141/2545-04.

The rapid expansion of production of North American petroleum crude oil from shale has led to a significant increase in rail transport of crude oil. Broken rails are frequent causes of train accidents. Ultrasonic rail defect inspection is widely used to prevent train accidents caused by broken rails, thereby reducing the hazardous materials transportation risk.…

Transitioning from flexible to structured heavy haul operations to expand the capacity of single-track shared corridors in North America

Dick, C.T., D. Mussanov and N. Nishio. 2019. Transitioning from flexible to structured heavy haul operations to expand the capacity of single-track shared corridors in North America. Journal of Rail and Rapid Transit. 233 (6): 629-639. doi:10.1177/0954409718804427.

North American freight railroads typically exhibit flexible operations with variable train schedules where freight trains are dispatched when filled to length or weight capacity, and train dispatchers resolve train conflicts in real time, making it an ideal approach for low-cost transportation of bulk commodities. Recently, North American railways have experienced a substantial decline in demand…

Improving railway operational efficiency with moving blocks, train fleeting and alternative single-track configurations

Diaz de Rivera, A., C.T. Dick and L.E. Evans. 2020. Improving railway operational efficiency with moving blocks, train fleeting and alternative single-track configurations. Transportation Research Record: Journal of the Transportation Research Board. 2674 (2): 146-157. doi:10.1177/0361198120905842.

With installation of positive train control (PTC) on many U.S. rail corridors, Class I railroads may soon leverage these investments in communications network infrastructure to implement ‘‘advanced PTC’’ systems incorporating moving blocks. Train control with moving blocks can benefit operating strategies that dispatch fleets of multiple trains running at minimum headways. On single-track corridors with…

Potential for moving blocks and train fleets to enable faster train meets on single-track rail corridors

Diaz de Rivera, A., C.T. Dick and L.E. Evans. 2020. Potential for moving blocks and train fleets to enable faster train meets on single-track rail corridors. Journal of Transportation Engineering, Part A: Systems. 146 (8): 04020077. doi:10.1061/JTEPBS.0000403.

On single-track rail corridors, meets between trains are a significant source of train delay. From the stopping train’s perspective, a meet can be divided into three distinct phases: braking into a siding, waiting for higher-priority trains to pass, and accelerating to operating speed on the main track. Meet delay can be further divided into fixed…

Relative capacity and performance of fixed and moving block control systems on North American freight railway lines and shared passenger corridors

Dick, C.T., D. Mussanov, L.E. Evans, G.S. Roscoe and T-Y. Chang. 2019. Relative capacity and performance of fixed and moving block control systems on North American freight railway lines and shared passenger corridors. Transportation Research Record: Journal of the Transportation Research Board. 2673 (5): 250-261. doi:10.1177/0361198119841852.

North American railroads are facing increasing demand for safe, efficient, and reliable freight and passenger transportation. The high cost of constructing additional track infrastructure to increase capacity and improve reliability provides railroads with a strong financial motivation to increase the productivity of their existing mainlines by reducing the headway between trains. The objective of this…

Relative train length and the infrastructure required to mitigate delays from operating combinations of normal and over-length freight trains on single-track railway lines in North America

Dick, C.T., I.A. Atanassov, F.B. Kippen III and D. Mussanov. 2019. Relative train length and the infrastructure required to mitigate delays from operating combinations of normal and over-length freight trains on single-track railway lines in North America. Journal of Rail and Rapid Transit. 233 (7): 731-742. doi:10.1177/0954409718809204.

Distributed power locomotives have facilitated longer heavy-haul freight trains that improve the efficiency of railway operations. In North America, where the majority of mainlines are single track, the potential operational and economic advantages of long trains are limited by the inadequate length of many existing passing sidings (passing loops). To alleviate the challenge of operating…

Operational Schedule Flexibility, Train Velocity and the Performance Reliability of Single-Track Railways

Freight shippers and travelers demand a consistent level of service from transportation systems, including railways. Inventory and train connections are more efficiently managed when the total time for railways to move freight or passengers between origin and destination is predictable. One approach to achieve consistency is structured operations where trains are dispatched according to predetermined…

Delay Performance of Different Train Types Under Combinations of Structured and Flexible Operations on Single-Track Railway Lines in North America

Determining Freight Train Delay Costs on Railroad Lines in North America

Delayed freight trains inflict costs on many different stakeholders including the railroad, shippers, and the public. Quantifying the cost of train delay experienced by each group of stakeholders is necessary to understand the impact of a track outage or other operational disturbance, or to conduct a benefit-cost analysis to justify potential line capacity improvements. The…

Exchange Point Delay and Mode Shift Associated with Regional Deployment of Alternative Locomotive Technology on the North American Line-Haul Freight Network