Modification of the Highway Capacity Manual two‐lane highway analysis procedure for Spanish conditions

The US Highway Capacity Manual (HCM) methodology is used in Spain to evaluate traffic operation and quality of service. The effect of passing manoeuvre on two‐lane highway operational performance is considered through adjustment factors to average travel speeds and percent time spent following. The procedure is largely based on simulations in TWOPAS and passing behaviours observed during US calibrations in the 1970s. It is not clear whether US driving behaviour and vehicles' performance are comparable with Spanish conditions. The objective of this research is to adapt the HCM 2010 methodology to Spanish driver behaviour, for base conditions (i.e. no passing restrictions). To do so, TWOPAS was calibrated and validated based on current Spanish passing field data. The calibration used a genetic algorithm. The case study included an ideal two‐lane highway with varying directional traffic flow rate, directional split and percentage of trucks. The updated methodology for base conditions is simpler than the current HCM 2010 and does not rely on interpolation from tables. Copyright © 2016 John Wiley & Sons, Ltd.     

Climate Change and Tourist Comfort on Europe's Beaches in Summer: A Reassessment

Major impacts of climate change have been projected for tourism in Europe. Typically, these projections took general tourism activities such as sight-seeing and their climate requirements as their point of reference. The purpose of this study is to reassess the impact of climate change, by looking specifically at beach tourism in summer, a crucial market segment in Europe and more specifically in the Mediterranean. As beach tourism requires relatively high temperatures, relatively modest shifts in attractiveness are found. With respect to climate, the Mediterranean is likely to remain Europe's prime region for summer-time beach tourism for at least the next 50 years. Coastal managers in Mediterranean destinations are advised to focus some of their attention on other climate change impacts such as sea-level rise or water availability, and include environmental quality and diversification of activities in their deliberations. In non-Mediterranean regions, a promising strategy may be to focus on short- and medium-distance visitors who can take advantage of the new opportunities for beach tourism, and to explore the merits of seasonal climate forecasting.     

Determinants of Efficiency at Major Brazilian Port Terminals

This paper reports on the use of different approaches for measuring the efficiency of major Brazilian port terminals. Two of the most important approaches, DEA (Data Envelopment Analysis) and SFA (Stochastic Frontier Analysis), were performed on data collected from 25 terminals. The findings indicate that the majority of Brazilian terminals are running short on capacity due to the export boom that has occurred over the past few years and due to the lack of investment in capacity expansion. Furthermore, efficiency measurements derived from a reduced model with only one input and one output were explained based on variables such as type of cargo handled (container or bulk), connectivity of the terminal to railroads, and control (state or private) of the terminal. Implications and directions for future research are explored.     

Origins,Management, and Measurement of Stress on the Coast of Southern Spain

A series of boater compliance studies was performed between 1995 and 1998 in order to assess the effectiveness of existing speed zones designed to protect manatees in two Florida counties (Sarasota County and Lee County). Surveys involved teams of boat- or land-based observers positioned along speed-restricted waterways. Vessel characteristics were recorded along with observed speed. Multiple survey sites were sampled within each county. A total of 26,000 vessels was observed and evaluated. Overall boater compliance was 63% in Sarasota County and 58% in Lee County. Compliance varied significantly with vessel type and size. Differences in compliance among survey sites were also significant and were related to travel patterns, traffic volume, vessel composition, sign placement, level of speed restriction, and law enforcement presence. From a management perspective, it is recommended that speed zones for the protection of manatees be evaluated on a site-by-site basis to identify specific areas of concern.     

Theoretical Comparison Between Different Configurations of Radial and Conventional Bogies

This article compares the dynamic behaviour of different configurations of radial and conventional two-axle bogies. In general, the design parameters for a better curve negotiation are not compatible with those for good stability. As the main target of this article is to compare the curving performances of different bogies under the same design basis, several bogie configurations with the same level of stability, obtained by choosing proper primary suspension stiffnesses, have been used. The comparison includes a conventional bogie and three radial bogies with differing self-steering and forced-steering principles in three different passenger services: High Speed, Regional and Mass Transit. The analysis has been concentrated on parameters such as stability, lateral wheel-track forces in curve and wheel wear indices. The results show that the radial bogie configurations studied do not make significant contributions in general applications with regard to a conventional bogie. It is only under specific running conditions and types of service that some radial bogie configurations provide advantages with respect to the conventional bogie.     

燃油二次喷射对柴油机燃烧和性能的影响

在Ricardo Hydra单缸柴油机上,采用一次主喷射+一次后喷射的方法进行了5组燃烧对比试验。示功图和缸内燃烧分析表明,两次喷射有效地延长了等压加热过程,平均有效压力得到较大的提高,NOx排放有一定幅度的下降。     

燃油2次喷射对柴油机性能的影响研究

研究了主喷射提前角和后喷射提前角对Ricardo Hydra单缸柴油机动力性能及排放性能的影响.结果表明.当该柴油机主喷射提前角为11°、后喷射提前角为3°时,柴油机最高爆发压力与采用单喷射时最高爆发压力相差不大,但平均有效压力却提高明显;随着喷油提前角的后移,烟度排放增加,NOx排放减少,HC排放增加.分析了主喷射和后喷射时该柴油机燃烧过程.     

Towards an enriched framework of service evaluation for pedestrian and bicyclist infrastructure: acknowledging the power of users’ perceptions

Transportation - More and more cities worldwide are striving for sustainability and livability. Measuring the service or performance of local-scale spaces for pedestrians and bicyclists to better...