Ontario Ministry of Transportation

About: Ontario Ministry of Transportation is a government organization based out in Toronto, Ontario, Canada. It is known for research contribution in the topics: Poison control & Asphalt. The organization has 4652 authors who have published 3882 publications receiving 59011 citations.

Eliminating Deck Joints Using Debonded Link Slabs: Research and Field Tests in Ontario

Abstract: One of the main factors affecting the durability of bridge structures is the presence of expansion joints at bridge support locations. The inability of current joint systems to provide reliable, long-term, leak-proof performance generally leads to early leakage of chloride-contaminated water through these joints, thereby causing premature corrosion in the deck elements below. This problem is particularly evident in older-type multispan bridges in which the girders are simply supported at the piers and are separated by expansion joints or simple paved-over joints. To address this problem, the Ministry of Transportation of Ontario (MTO) has recently rehabilitated a number of bridge decks using a debonded link slab system to replace the deck joints at the pier locations. To get a better understanding of the performance and reliability of this new rehabilitative technique, MTO recently carried out an experimental research study of the long-term performance of the system on scale test models that were subjected to extensive cyclic loading in the laboratory. At the same time, it carried out a load test of a recently rehabilitated structure to study its structural behavior both before and after the link slab was constructed. The test structure was instrumented with sensors that measured deflections and strains in the link slab and girders. This paper describes the experimental research study and the behavioral load tests that were carried out, and discusses the results obtained. The experimental study showed that the long-term performance of the link slab was not affected by the extensive cyclic loading to which the model was subjected, whereas the load testing of the test structure showed that it satisfied the serviceability limit state requirements of the Canadian Highway Bridge Design Code, thus validating the design methodology of the system.

Sampling and Partition of Neutral Organic Contaminants in Surface Waters With Regard to Legislation, Environmental Quality and Flux Estimations

Abstract: The distribution of neutral organic contaminants among the different phases in surface water is predicted from the octanol—water partition coefficient (Kow), resulting in a reasoned sampling approach. Most pitfalls in methodology of sampling and the determination of partition coefficients appear to origin from adsorption. For contaminants with Kow values <10 4 environmental quality of surface waters, represented by the truly dissolved contaminants, can be determined by simply sampling the dissolved phase. For more hydrophobic contaminants sampling suspended particulate matter (SPM) is prefered as this method is hardly afflicted by adsorption problems. The contaminants truly dissolved content then can be estimated through the partition coefficient. Results of the SPMs contaminant contents, expressed per weight units organic carbon, allow spatial and temporal comparison to be achieved. Estimating fluxes of contaminants, mainly bound to organic matter (particulate and/or colloidal), should be focuse...

Frequency and Duration Concepts in System Reliability Evaluation

Abstract: This paper develops a mathematical theory associated with frequency and duration methods in system reliability evaluation. The approach is based upon the concept of frequency as an expectation of the state encounter rate. These concepts are then used to derive the basic conditions for mergeability which are very useful when evaluating the reliability of large systems.

Ontario's wet pavement accident reduction program

Abstract: Ontario's approach to the identification and treatment of black spot highway locations is presented. Highway locations with an excessive rate of wet pavement accidents are identified and ranked utilizing Ontario Ministry of Transportation and Communications computerized accident data files. Criteria for site selection, procedures for subsequent site investigation, and selection of appropriate remedial measures are outlined and discussed. Rehabilitation of pavements with low friction levels, and experiencing a high rate of wet pavement collisions, has resulted in substantial reductions in accidents. Collision data before and after treatment at various sites are presented. This paper provides design and performance information on modified bituminous surface course mixes currently used by the Ministry. Such mixes maintain better surface textures and provide longer lasting skid resistance characteristics. These mixes are used for black spot treatments, and in new surface construction on main highways.

Variations in Queue Discharge Patterns and Their Implications in Analysis of Signalized Intersections

Abstract: Saturation flow is traditionally treated as a stabilized maximum rate at which queuing vehicles can be discharged from a lane after the signal changes to green. Traffic engineers in many countries have been using this parameter to estimate the capacities of traffic lanes at signalized intersections. The estimated capacities in turn are used to estimate other performance measures and to classify levels of service. This traditional method of analysis is an efficient way for capacity estimation if the queue discharge rate rises quickly to a steady maximum after onset of the green signal. Actual queue discharge patterns, however, often do not display an easily identifiable steady maximum rate. This characteristic renders the use of saturation flow troublesome and prone to errors that can lead to poor planning and operational decisions. The pitfalls in the current use of saturation flow are examined, and ways of alleviating the problems are suggested.