Development of techniques and data for evaluating ride quality. Volume II: ride-quality research. Final report.

Transportation Department, Research and Special Programs Directorate, Washington, D.C.

Development of a systems risk methodology for single and multi-modal transportation systems. Final report.

Transportation Department, Research and Special Programs Administration, Washington, D.C.

Collision avoidance and accident survivability. Volume 4: Proposed specification. Final report.

Transportation Systems Center, Cambridge, Mass.

Studies of freight train engineer performance. Final report.

Federal Railroad Administration, Office of Research and Development, Washington, D.C.

Energy and economic impacts of projected freight transportation improvements. Final report.

Transportation Systems Center, Cambridge, Mass.

Multidisciplinary accident investigation - school bus locomotive-caboose collision, Lafayette, Oregon, September 8, 1976. MDAI team report.

National Highway Traffic Safety Administration, Washington, D.C.

BART in the San Francisco Bay Area - the final report of the BART Impact Program.

Transportation Department, Washington, D.C.

Environmental impacts of BART: interpretive summary of the final report.

Transportation Department, Washington, D.C.

The impact of BART on economics and finance - interpretive summary of the final report.

Transportation Department, Washington, D.C.

Land use and urban development impact of BART: interpretive summary of the final report.

Transportation Department, Washington, D.C.

Collision avoidance and accident survivability. Volume 1: collision threat. Final report.

Transportation Systems Center, Cambridge, Mass.

Amtrak: financial condition has deteriorated and future costs make recovery difficult.

Mode of access: Internet.

Obstacle-free range determination for rail track maintenance vehicles

Maintenance trains travel in convoy. In Australia, only the first train of the convoy pays attention to the track sig- nalization (the other convoy vehicles simply follow the preceding vehicle). Because of human errors, collisions can happen between the maintenance vehicles. Although an anti-collision system based on a laser distance meter is already in operation, the existing system has a limited range due to the curvature of the tracks. In this paper, we introduce an anti-collision system based on vision. The two main ideas are, (1) to warp the camera image into an image where the rails are parallel through a projective transform, and (2) to track the two rail curves simultaneously by evaluating small parallel segments. The performance of the system is demonstrated on an image dataset.

Safety assessment of underground vehicles passing over highly resilient straight tracks in the presence of a broken rail

In this paper, vehicle-track interaction for a new slab track design, conceived to reduce noise and vibration levels has been analyzed, assessing the derailment risk for trains running on curved track when encountering a broken rail. Two different types of rail fastening systems with different elasticities have been analysed and compared. Numerical methods were used in order to simulate the dynamic behaviour of the train-track interaction. Multibody system (MBS) modelling techniques were combined with techniques based on the finite element method (FEM). MBS modelling was used for modelling the vehicle and FEM for simulating the elastic track. The simulation model was validated by comparing simulated results to experimental data obtained in field testing. During the simulations various safety indices, characteristic of derailment risk, were analysed. The simulations realised at the maximum running velocity of 110 km/h showed a similar behaviour for several track types. When reducing the running speed, the safety indices worsened for both cases. Although the worst behaviour was observed for the track with a greater elasticity, in none of the simulations did a derailment occur when running over the broken rail.

Safety assessment of underground vehicles passing over highly resilient curved tracks in the presence of a broken rail

Vehicle–track interaction for a new resilient slab track designed to reduce noise and vibration levels was analysed, in order to assess the derailment risk on a curved track when encountering a broken rail. Sensitivity of the rail support spacing of the relative position of the rail breakage between two adjacent rail supports and of running speed were analysed for two different elasticities of the rail fastening system. In none of the cases analysed was observed an appreciable difference between either of the elastic systems. As was expected, the most unfavourable situations were those with greater rail support spacing and those with greater distance from the breakage to the nearest rail support, although in none of the simulations performed did a derailment occur when running over the broken rail. When varying the running speed, the most favourable condition was obtained for an intermediate speed, due to the superposition of two antagonistic effects.