Passenger car equivalents (PCEs) are used in highway capacity analysis to convert a mixed vehicle flow into an equivalent passenger car flow. This calculation is relevant to capacity and level of service determination, lane requirements, and determining the effect of traffic on highway operations. The most recent Highway Capacity Manual 2000 reports PCEs for basic freeway segments according to percent and length of grade and proportion of heavy vehicles. Heavy vehicles are considered to be either of two categories: trucks and buses or RVs. For trucks and buses, PCEs are reported for a typical truck with a weight to power ratio between 76.1 and 90.4 kg/kW (125 and 150 lb/hp). The weight to power ratio is an indicator of vehicle performance. Recent development of vehicle dynamics models make it possible to define PCEs for trucks with a wider variety of weight to power ratios. PCEs were calculated from the relative impact of trucks on traffic density using the simulation model INTEGRATION. The scope of this research was to evaluate PCEs for basic freeway segments for trucks with a broader range of weight to power ratios. Such results should make freeway capacity analysis more accurate for mixed vehicle flow with a non-typical truck population. In addition, the effect of high proportion of trucks, pavement type and condition, truck aerodynamic treatment, number of freeway lanes, truck speed limit, and level of congestion was considered. The calculation of PCEs for multiple truck weight to power ratio populations was not found to be different from single truck weight to power ratio populations. The PCE values were tabulated in a compatible format to that used in the Highway Capacity Manual 2000. / Master of Science

Esta pesquisa avaliou o efeito do uso de uma medida de desempenho alternativa à densidade no cálculo dos fatores de equivalência para caminhões típicos em rodovias de pista dupla do estado de São Paulo. A medida de desempenho investigada foi a velocidade dos automóveis e os fatores de equivalência foram calculados pelo método do equivalente médio, que considera mais de um tipo de caminhão na corrente de tráfego, representa melhor a interação entre caminhões e permite o uso de simulação de tráfego para determinação dos equivalentes. Como este método de cálculo considera uma composição fixa de caminhões, o tráfego de caminhões em rodovias paulistas de pista dupla foi caracterizado em função de dois aspectos: (1) o fluxo veicular em dias úteis típicos e (2) o desempenho das configurações de caminhões, a partir da relação massa/potência. O modelo de simulação utilizado nesta pesquisa foi o CORSIM, o mesmo modelo usado no HCM-2000. Para tanto, o CORSIM foi calibrado para as condições observadas em rodovias paulistas de pista dupla. A calibração foi realizada em duas etapas, ambas baseadas em algoritmos genéticos: a primeira etapa focou no modelo de locomoção dos caminhões, resultando erros médios da ordem de 5%; a segunda visou à lógica de car-following, que define o comportamento dos motoristas. A versão calibrada do CORSIM para as condições paulistas apresentou erros médios de 6,32% na calibração e de 6,58% na validação. Os equivalentes veiculares foram calculados para diferentes magnitudes de greides, comprimentos de rampas, porcentagens de caminhões, velocidade de fluxo livre e níveis de serviço, tanto para a velocidade dos automóveis como para a densidade. Como resultado final, observou-se que o uso da velocidade dos automóveis como medida de desempenho implica em equivalentes veiculares muito elevados. Desta forma, a capacidade de tráfego e o nível de serviço estimado utilizando estes equivalentes foram piores do que utilizando os equivalentes veiculares obtidos com a densidade como medida de desempenho. / The objective of this research was to evaluate the use of a measure of impedance alternative to density to obtain passenger-car equivalence factors for typical trucks on multilane highways in the state of São Paulo. The impedance investigated was the passenger-car speed, and the equivalence factors were obtained through the average equivalent method since it considers different types of trucks within the traffic flow, is capable to represent interactions among trucks adequately, and allow the use of traffic simulation. Since the estimation method employed is based on a fixed truck population, the truck flow on multilane highways in the state of São Paulo was characterized based on two aspects: (1) a typical traffic flow, considering the traffic flow on typical weekdays, (2) the truck performance based on mass/power ratio. The simulation model employed was CORSIM, the same model used in the HCM-2000, and it was calibrated for the conditions observed in multilane highways in the state of São Paulo. The calibration was carried out using genetic algorithms and involved two steps. The first one focused on the truck motion model and produced average errors around 5%. The second one focused on the car-following logic that defines the drivers\' behavior. The CORSIM calibrated for the state of São Paulo highways produced average errors of 6.32% at the calibration stage and average errors of 6.58% at the validation stage. Passenger-car equivalents were calculated for different grade levels, grade lengths, trucks percentages, free-flow speeds and leves of service using passenger-car speed and density as the impedance measure. It was observed that, when compared to density, the use of passenger-car speed as a measure of impedance results in higher values for the equivalence factors. It means smaller capacities and worse estimates for level of service.

Esta pesquisa avaliou o efeito do uso de uma medida de desempenho alternativa à densidade no cálculo dos fatores de equivalência para caminhões típicos em rodovias de pista dupla do estado de São Paulo. A medida de desempenho investigada foi a velocidade dos automóveis e os fatores de equivalência foram calculados pelo método do equivalente médio, que considera mais de um tipo de caminhão na corrente de tráfego, representa melhor a interação entre caminhões e permite o uso de simulação de tráfego para determinação dos equivalentes. Como este método de cálculo considera uma composição fixa de caminhões, o tráfego de caminhões em rodovias paulistas de pista dupla foi caracterizado em função de dois aspectos: (1) o fluxo veicular em dias úteis típicos e (2) o desempenho das configurações de caminhões, a partir da relação massa/potência. O modelo de simulação utilizado nesta pesquisa foi o CORSIM, o mesmo modelo usado no HCM-2000. Para tanto, o CORSIM foi calibrado para as condições observadas em rodovias paulistas de pista dupla. A calibração foi realizada em duas etapas, ambas baseadas em algoritmos genéticos: a primeira etapa focou no modelo de locomoção dos caminhões, resultando erros médios da ordem de 5%; a segunda visou à lógica de car-following, que define o comportamento dos motoristas. A versão calibrada do CORSIM para as condições paulistas apresentou erros médios de 6,32% na calibração e de 6,58% na validação. Os equivalentes veiculares foram calculados para diferentes magnitudes de greides, comprimentos de rampas, porcentagens de caminhões, velocidade de fluxo livre e níveis de serviço, tanto para a velocidade dos automóveis como para a densidade. Como resultado final, observou-se que o uso da velocidade dos automóveis como medida de desempenho implica em equivalentes veiculares muito elevados. Desta forma, a capacidade de tráfego e o nível de serviço estimado utilizando estes equivalentes foram piores do que utilizando os equivalentes veiculares obtidos com a densidade como medida de desempenho. / The objective of this research was to evaluate the use of a measure of impedance alternative to density to obtain passenger-car equivalence factors for typical trucks on multilane highways in the state of São Paulo. The impedance investigated was the passenger-car speed, and the equivalence factors were obtained through the average equivalent method since it considers different types of trucks within the traffic flow, is capable to represent interactions among trucks adequately, and allow the use of traffic simulation. Since the estimation method employed is based on a fixed truck population, the truck flow on multilane highways in the state of São Paulo was characterized based on two aspects: (1) a typical traffic flow, considering the traffic flow on typical weekdays, (2) the truck performance based on mass/power ratio. The simulation model employed was CORSIM, the same model used in the HCM-2000, and it was calibrated for the conditions observed in multilane highways in the state of São Paulo. The calibration was carried out using genetic algorithms and involved two steps. The first one focused on the truck motion model and produced average errors around 5%. The second one focused on the car-following logic that defines the drivers\' behavior. The CORSIM calibrated for the state of São Paulo highways produced average errors of 6.32% at the calibration stage and average errors of 6.58% at the validation stage. Passenger-car equivalents were calculated for different grade levels, grade lengths, trucks percentages, free-flow speeds and leves of service using passenger-car speed and density as the impedance measure. It was observed that, when compared to density, the use of passenger-car speed as a measure of impedance results in higher values for the equivalence factors. It means smaller capacities and worse estimates for level of service.

Multi-combination vehicles (MCVs) in urban areas impact on productivity, safety, infrastructure, congestion and the environment. However, psychological effects of MCVs on other drivers may also influence the positioning of vehicles and congestion. A literature review revealed little information on the psychological effects of heavy vehicles on other road users. This research can be used to quantify some psychological impacts of MCVs. A testing program was undertaken on the Gateway Motorway to observe passenger car behaviour around MCVs in a lateral and longitudinal sense. Video footage was collected on a four lane divided urban motorway section which was level, straight and away from any off/on ramps. It experiences high traffic volumes with a one-way AADT of approximately 33,500. The route is currently designated for B-doubles, which is the most common MCV in urban areas. In a lateral sense, the research showed that passenger car behaviour changes around heavy vehicles (prime mover semi-trailer combination and B-doubles); however, there is no statistical difference in passenger car behaviour around semi-trailers and B-doubles. Longitudinally it was found that, even though passenger cars shy away from B-doubles more than semi-trailers, B-doubles are still more efficient in a spatial sense since they carry more freight. The outcomes of this research indicate that there is no further psychological impact on passenger cars, when travelling around B-doubles compared with semi-trailers. Where the results identified longitudinal behaviour changes, it was still concluded that B-doubles were more efficient at transporting freight when the passenger car equivalent (PCE) per tonne of freight was considered. Tracking ability testing was undertaken in a rural area to determine the lateral spatial requirements of three different MCVs. The rural testing was considered appropriate since parts of the urban network have similar characteristics to rural networks. A model was developed as a part of this project to process the data collected by Haldane (2002), but results could not be relied upon due to poor quality data.