Abstract

Vietnam's transport sector plays an important role in its socioeconomic development. Passenger transport helps meets daily needs and contributes significantly to tourist service development while freight transport helps meet the country's demand for delivery of raw materials and of semi-finished products to production facilities and for transport of finished products to consumers. With the overall growth in transport in the country, each of the main forms of transport (road, railway, aviation, inland waterways and maritime) are currently increasing the total fuel use for transport and as a result overall greenhouse gas emissions. In addition to the mix of transport modes used, the major factors affecting the impact of this growth on current and future greenhouse gases from each mode of transport are the quality and quantity of the vehicles and supporting infrastructure and the type of fuels used and their efficiency. The following sections evaluate the infrastructure and fuel use of each of the modes of transport (sections 1.1-1.5), the current and projected greenhouse gas emissions from the sector and the reasons for this (section 2), and typologies of interventions that can reduce the emissions from the sector (section 3).

Abstract

The U.S. Highway Capacity Manual (HCM 2010) methodology is used in Spain to evaluate traffic operation and quality of service. In two-lane undivided highways, the effect of limiting where drivers could pass slower vehicles, or passing restrictions, is considered through the percentage of no-passing zones. This measure does not account for how passing opportunities are distributed along the road. The objective of this research was to evaluate the effect percentage of no-passing zones and average passing zone length on a two-lane highway and, if significant, incorporate them in the analysis methodology,. The TWOPAS microsimulation program was calibrated and validated to the Spanish conditions. Passing restrictions had little effect on average traffic speed (ATS), with differences lower than 6 km/h between a road segment with no passing restrictions and a road segment with a passing restriction on 100% of its length. Conversely, passing restrictions can increase the percent time spent following (PTSF) up to 30%. Increasing the passing zone length beyond 2,000 m does not improve PTSF. The new models could be used to better estimate traffic operation on Spanish two-lane highways. Document type: Article