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This paper focuses on modeling of Hot Mix Asphalt (HMA) material behavior during compaction. During compaction the particle configuration inside the HMA is changing from a relatively loose into a denser one while the bitumen is fluid. Initially particle reorientation is easily possible due to the HMA's loose configuration. The material behavior predominantly falls in the elastic-plastic domain. Critical state theory from soil mechanics is proposed as a basis for modeling this behavior. An extensive laboratory testing program was undertaken using a modified Hveem stabile meter as a tool for parameterization. The program included: different mixtures, different stages of mixture density and different material temperatures. In this paper, we discuss how well the critical state principles suit HMA behavior, and what the critical state material parameters are for HMA with respect to different material temperatures, different compaction stages and different stress states. We show that HMA compaction behavior can be modeled using the critical state theory and that material behavior is bi-linear in the p':q stress space. [ABSTRACT FROM AUTHOR]

An introduction is presented in which the editors discuss various reports within the issue on topics including the use of geographic information system (GIS) in road accident mapping, spatial data acquisition techniques, and the use of GIS in travel demand forecasting.

Geospatial data is urgently needed in decision-making processes to achieve Sustainable Development Goals (SDGs) at global, national, regional and local scales. While the advancement of geo-technologies to obtain or produce geospatial data has become faster and more affordable, many countries in the global south still experience a geospatial data scarcity at the rural level due to complex geographical terrains, weak coordination among institutions and a lack of knowledge and technologies to produce visualised geospatial data like maps. We proposed a collaborative spatial learning framework that integrates the spatial knowledge of stakeholders to obtain geospatial data. By conducting participatory mapping workshops in three villages in the Deli Serdang district in Indonesia, we tested the framework in terms of facilitating communication and collaboration of the village stakeholders while also supporting knowledge co-production and social learning among them. Satellite images were used in digital and non-digital mapping workshops to support village stakeholders to produce proper village maps while fulfilling the SDGs' emphasis to make geospatial data available through a participatory approach. [ABSTRACT FROM AUTHOR]

This paper presents a meta-analysis of studies that have evaluated the effects of an edgeline on speed and lateral position of motorised road users. Together with many other study characteristics, 41 estimates of the effects of an edgeline on speed and 65 on lateral position were extracted from the studies. The results of the evaluation studies show a great variety in effects. Both negative and positive effects on speed and lateral position were found; amongst others, increases in speed up to 10.6 km/h, as well as decreases in speed up to 5.0 km/h, and shifts of the lateral position towards the centre of the road up to 30 cm, as well as shifts towards the edge of the road up to 35 cm. Further analyses resulted in the determination of study characteristics that influence the effects of an edgeline on speed and lateral position. It is concluded that the effects of an edgeline on speed are related to the presence of a centreline. Applying an edgeline to a road without a centreline increases the speed of road users, and replacing a centreline by an edgeline decreases the speed. Results with respect to adding an edgeline to a road with a centreline were unclear. Another conclusion is that shoulder width and road environment contribute to the effects of an edgeline on lateral position. In combination with wide shoulders or buildings and/or trees next to the road, edgelines lead to shifts of the lateral position towards the edge of the road, and in combination with narrow shoulders or open fields, edgelines lead to shifts towards the centre of the road.