Abstract: Rail is today a minimally used modality in urban freight distribution. To reap the benefits of this more sustainable transport mode a few experiences in Europe have attempted to introduce innovative freight distribution schemes where rail is used. One of such schemes uses rail for the urban penetration leg. After having been consolidated in a centre located outside the urban area, goods are transported by shuttle trains to a centre located inside the central area (the multi-modal urban distribution centre – MUDC) and there are transferred to low-pollution road vehicles to reach their final destination. Other schemes use tramways.
The paper provides a review of rail-based schemes which have been introduced in European cities. An in-depth assessment is provided of the scheme based on the use of a MUDC. The case study relates to the distribution of fish food in Rome. The environmental and energy benefits obtainable from the shift from the current road-only scheme to the MUDC scheme are estimated in physical and monetary units. An estimate is provided of the maximum public contribution that would still make the scheme beneficial for society as a whole, obtained as the difference between the social costs of the road-only scheme and those of the MUDC scheme. Also, an assessment is provided of the profitability of the scheme from the operators‟ viewpoint.
Abstract: Thanks to vehicle automation, a new generation of urban transport systems that can supply car-like quality of service with Public Transport-like impacts was made possible. They are called Advanced Public Transport Systems and consist of small automated collective vehicles running on demand.
A pre-design method for a first dimensioning of such systems was developed by simulating nearly 3 000 scenarios with Dial-A-Ride software and performing statistical regressions on the results.
The method needs as input: network length, expected demand, vehicle top speed, maximum waiting time, and vehicle capacity. In six steps the method gives: number of vehicles, average waiting time, vehicleâ‹…kilometers, commercial speed, occupancy rate, and costs.
The regressions are given for 20-place vehicles, 15 km/h top speed, and 1 000 s waiting time CTS. All the R 2 coefficients are higher than 0.75 and in most cases than 0.85.
Empirical validations, made by comparing pre-design regressions with other system data, showed that the method gives accurate results.
Abstract: Introduction
Hybrid technology is seen by many as a potential solution to reduce vehicle emissions in cities. However type approval tests of hybrid vehicles measure emission levels comparable to those of conventional cars in the same market segment. It has been argued that type approval tests do not represent the reality of emission in cities therefore, to quantify the real emission of hybrids and to compare them with those of conventional vehicles in the same conditions, an emission measurement campaign was organised.
Acquisition campaign
Three Honda cars, one conventional (the Civic 2.0) and two hybrids (the Civic IMA and the Civic Hybrid), equipped to collect emissions as well as the engine and vehicle working parameters were driven three times by twenty drivers on the same urban route. Drivers were asked to drive normally and not requested to do anything special but to scrupulously follow the given itinerary.
Results
Two main results were obtained: average and maximum emission levels for the three cars are quantified; the effects of the drivers on such levels assessed. The conventional car (with two people and 250 kg of measurement tools onboard) consumes an average of 12.6 l/100 km, its CO2 emissions range between 200 g/km and 300 g/km with an average of 260 g/km. CO emissions range between 0.25 g/km and 6.25 g/km (Euro IV limit is 1 g/km) with an average of 2 g/km. The most recent of the two tested hybrids consume in average 8.23 l/100 km and emits between 150 and 230 g/km of CO2 with an average of about 180 g/km; it emits virtually no CO in the majority of cases but can reach up to 1.8 g/km and average CO emissions are about 0.2 g/km. The hybrid performs always better than the conventional; in terms of CO2 and consumption it can have up to a 30% reduction and in terms of CO up to 90% reduction.
Conclusions
The wideness of the measured ranges depends mostly on the drivers. Women tend to consume and emit less than men. The reason for this is the different way they use the accelerator pedal; they push it less and keep it steadier. In other word the standard deviation of the accelerator position (or throttle) is lower. It is here shown how a correlation exist between the throttle standard deviation and the emissions which justify using such parameter as the indicator of drive-style.
Abstract: A general evaluation methodology is presented for Advanced Transportation Systems, which can be applied for other ITS applications. It includes three phases: initial, ex-ante and ex-post, and is based on measurements of several sets of indicators. Results are presented for sites studied in the EU CityMobil and for energy management and optimization. Cross comparisons enable recommendations for adoption and implementation of sustainable urban CTS. System optimization can be achieved, leading to reduced energy consumption and emission of pollutants and greenhouse gases. It is noted that the first ever large scale PRT is under construction now at the Heathrow Airport.
