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The optimum strategy for mode choice modelling of interregional fish transport considering shippers' heterogeneity

Ansu V., Anjaneyulu M. V. L. R.

Archives of Transport

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2022

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Vol. 64, iss. 4

7--26

EN

The determinants of mode choice of interregional transport of fish, which is highly perishable, vastly differ from that of other commodities. These determinants are to be identified to improve transport efficiency. A questionnaire survey of shippers is used to collect the data. Highly correlated observed variables are combined to form four latent factors by factor analysis to reduce the errors in modelling. Logical relations among the component variables of latent factors are perceived, and mathematical formulations are used to estimate new variables. It is found that transportation costs and shipment weight contributes to factor 1, while distance contributes to factor 2. However, transportation costs are associated with distance and shipment weight. Thus, the variable, transportation cost per q-km, is estimated. Survey respondents' attitudes are also incorporated into modelling by including qualitative factors obtained by the factor analysis of shippers' preference ratings. A latent class analysis confirmed the existence of heterogeneity among shippers. Misrepresentations of effects occur in modelling if the heterogeneity in the data is not considered. No studies have found the best combination of observed variables, latent factors, estimated variables, and qualitative factors, considering shippers' heterogeneity in freight mode choice. Hence, this study is done to find the optimum modelling strategy. Modelling revealed that models built with estimated variables outperformed those built with latent factors. Including qualitative factors along with observed variables and estimated variables showed further improvement. However, the model that includes observed variables, estimated variables, and qualitative factors considering shippers' heterogeneity is the best. It was found that the mode selection behaviour of different latent classes of shippers is distinct. A mode shift from road to rail could be achieved by lowering transportation costs and increasing speed, reliability, and safety for fish transport. Expanding roll on-roll off facilities, dedicated freight corridors, parcel trains, refrigerated containers, and piecemeal service by rail promote a mode shift from road to rail and reduce energy usage.

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Geometric factors influencing entry capacity of roundabouts under heterogeneous traffic conditions

Zacharia Arun Baby, Madhavan Harikrishna, Anjaneyulu M. V. L. R.

Archives of Transport

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2019

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Vol. 49, iss. 1

87--101

EN

Roundabout entry capacity is influenced by geometric features of the roundabout, traffic flow characteristics, vehicle are checked. In comparison with the existing empirical models such as the LR942 regression model and German empirical model, the proposed regression model produced better estimates and much lower RMSE values. Approach width is found to have the highest impact on entry capacity. The entry capacity is found to be negatively influenced by entry angle. Circulating flow is considered in terms of per metre width against the usual convention. This modification incorporates the effect of circulatory roadway width also into consideration. The circulatory roadway width has a diverse effect on entry capacity at different levels of circulating flow. Modification of inscribed circle diameter and circulatory roadway width is suggested as a potential solution for improving entry capacity. Sensitivity analysis is carried out to quantify the effect of variation of entry angle, circulatory roadway width, inscribed circle diameter and approach width on entry capacity based on the non-linear model. The sensitivity plots can be used to make subtle geometric modifications to improve capacity at congested roundabouts.

3

Activity-travel patterns of workers and students: a study from Calicut city, India

Babu D., Balan S., Anjaneyulu M. V. L. R.

Archives of Transport

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2018

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Vol. 46, iss. 2

21--32

EN

Travel behaviour studies in activity-based perspective treat travel as a result of individual’s desire to participate in different activities. This approach is more significant in the context of developing countries, as the transportation problems are more severe here. Since, commuters contribute to a major share in the travel, understanding their travel behaviour is essential. This paper aims to explore the travel behaviour of commuters in Calicut city, Kerala State, India and thereby model their activity-travel patterns. Household, personal and activity-travel information from 12920 working people and 9684 students formed the database for this study. The data collection was performed by means of home-interview survey by face-to-face interview technique. From preliminary analysis, several simple and complex tours were identified for the study area. Working people’s work participation and students’ education activity participation decision are modelled as mandatory activity participation choice in a binary logit modelling framework. Results of this mandatory activity participation model revealed that male workers are more likely to engage in work compared to females. Presence of elderly persons is found to negatively influence the work participation decisions of workers. This may be due to the fact that, work activity may be partially or completely replaced with the medical requirements of the elderly. The chances for work activity participation increase with increase in number of two-wheelers at home. In the case of students, as the education level increases, they are found to be less likely to participate in education activities. Students are observed to follow simple activity-travel pattern. Complex tours are found to be performed by males, compared to females. Activity-travel pattern of the study group are predicted using the developed models. The percentages correctly predicted indicate reasonably good predictability for the models. These kind of studies are expected to help the town planners to better understand city’s travel behaviour and thus to formulate well-organised travel demand management policies.