A Modified ACO with K-OPT for Restricted Covering Salesman Problems in Different Environments

In this study, the ant colony optimization (ACO) algorithm is modified with the K-opt operation to solve the covering salesman problem(CSP) under one restriction in crisp and imprecise (fuzzy, rough) environments. A CSP involves two phases- the division of cities into groups with the selection of the visiting cities and searching of the Hamiltonian circuit through the visiting cities. But, none of the studies in the literature is made following the direct approach. Also, none of the studies in the literature gives attention to reduce the total travel distance of the unvisited cities from the visited city of a group. Moreover, there is no algorithm in the literature which provides the solution of a CSP with the specified coverage range $r$. Also, none has introduced any algorithm to solve CSPs in imprecise environments. Though algorithms are available to solve the Traveling Salesman Problems in the imprecise environments, the approach cannot deal with the problems involving fuzzy data with non-linear membership functions or the problems involving rough data where the rough estimation can not be done using Lebesgue measure. The well establish algorithm for any routing problem is the ACO, but not much attention has been paid to solve the CSP using ACOs. To overcome these limitations on the studies of the ACO on the CSPs, here, an algorithm is proposed for the division of groups of the set of cities depending upon the maximum number of cities in a group and the total number of groups. Then ACO is used to find the shortest/minimum-cost path of the problem by selecting only one visiting the city from each group without violating the restriction of the specified coverage range $r$ of the location of the unvisited cities. K-opt operation is applied periodically at the end of ACO operation to improve the quality of the best found solution so far by the ACO algorithm and to arrest any premature convergence. For the restricted problems paths are searched in such a manner that the total distance/travel cost of different unvisited cities of a group from the visited city of the group should not exceed a predefined upper limit. To solve the problem in an imprecise environment some approach is followed so that the tour is searched without transferring the imprecise optimisation problem into an equivalent crisp optimisation problem. Also, the simulation approaches in fuzzy and rough environments are proposed to deal with the CSPs with any type of estimation of the imprecise data set. Algorithm is tested with the standard benchmark crisp problems available in the literature. To test the algorithm in the imprecise environments, the imprecise instances are derived randomly from the standard crisp instances using a specified rule. Test results imply that the proposed algorithm is efficient enough in solving the CSPs in the crisp as well as in the imprecise environments.

Flying High in Academia—Willingness of University Staff to Perform Low-Carbon Behavior Change in Business Travel

This study aims to explore the factors that influence business travel decisions of university staff, in particular the extent and ways in which they are willing to reduce emission-intensive air travel, and the personal and structural barriers to such behavior change. Three strategies to reduce air travel were investigated: abstaining from particular events, substituting travel through virtual participation and mode shifting to ground-based public transport. We tested the effects of (1) specific decision factors for engaging in long-distance travel, choosing specific modes of travel and choosing virtual solutions; (2) former travel activities; (3) postponed trips due to COVID-19; and (4) sociodemographic factors, on the willingness of individuals to reduce air travel in a sample of university employees. We calculated regression models for the three strategies and added a qualitative analysis of open-ended comments. Former travel behavior as well as pro-environmental considerations play significant roles, influencing the willingness of employees to change their business travel behavior. Furthermore, we found that willingness to reduce air travel depends on the scope of behavior change. Although travel behavior is unevenly distributed across different subgroups, sociodemographic factors only play a minor role in the regression models. The present study adds to the limited body of quantitative research on the reduction potential of academic air travel, presenting an examination of university staff's willingness to change their long-distance travel behavior. Implications for university polices are discussed.

The Impact of Geo-Spatial Distribution of Markets on Household Travel Patterns in Akure Metropolis, Nigeria

This study examines the spatial distribution of markets and its impact on household travel patterns in Akure, Nigeria. Both primary and secondary data were utilized for the research. The coordinates of locations of markets were obtained using a hand held Geographical Position System (GPS) and determined by measured using the ‘Ruler’ menu of ArcGIS 10.3.1 software. A structured questionnaire was designed to elicit information on household travel patterns. Using descriptive and inferential statistics, the findings reveal that market is randomly distributed. A linear association exits between distance travel to market and household mode choice of transportation and it is significant at 0.05%. Inadequate transport services and traffic congestion are problems faced by households in Akure on their trips to markets. The study concludes that more periodic or daily markets should be provided in some localities that do not have in Akure and similar other cities in Nigeria.

“You can go out 14 miles away with the knowledge that you’ve got the battery to help you back if you need it!” Narratives of ranging behaviour and wellbeing in diaries of e-bike trial participants.

Increasing use of electric power assisted bikes (‘e-bikes’) could play a significant part in expanding the variety of people participating in cycling and contribute to replacing a greater range of journeys that are currently made by car. E-bike use is growing across the Europe and the UK government has committed to establishing a national e-bike support programme (DfT, 2020). This may have a significant impact on the requirements for planning and designing cycle infrastructure. Authorities will need to consider where e-bikes fit within wider policies to promote zero-emission cities. This paper draws on data from a large study on cycling and wellbeing - XXXXXX. Thirty-eight participants aged 50 and over, returning to cycling after a hiatus, were asked to keep a ‘Diary of Cycling Experience’ (DoCE) to record how their experiences of using an e-bike unfolded during an eight-week trial period. Standard tests pre and post revealed that e-bikes, through enabling increased physical activity and engagement with the outdoor environment, can provide positive benefits to cognitive function and wellbeing as reported in XXXXXX (XXXX). The paper expands these findings, drawing specifically on the qualitative component, namely the written and visual material provided in participant diaries to reveal the embodied nature of e-biking, and in particular, the opportunity it provided for longer distance travel, (re)discovery of spaces and places, and human flourishing. It argues for a reappraisal of what constitutes ‘active’ travel and what this might mean for the emerging practice of e-biking in relation to longer distance cycling, for different purposes and in different contexts. This is particularly pertinent in the context of an ageing society, the push towards zero-emission cities and the need to ensure socially inclusive mobility particularly in the time of Covid.Keywords: e-bikes; diary approach; ageing; wellbeing; social inclusion.

Distance, Time, Speed & Energy: A socio-political analysis of technologies of longer distance cycling

The basic laws of motion governing cycling are wellunderstood. Consideration of the variables of energy use in cycle travel areless frequent. The potentials of both aerodynamically efficient cycle designand the augmentation of human power with e-motors dramatically reconfigure whatwe understand as a cycle and as cycling. The prospect of increasing travel distance in regularjourneying, coupled with the logical application of augmentation (aerodynamicand/ or power), suggest a need to re-evaluate some of the ground expectationsapplied in design and planning for cycle travel if the cycles being designedfor do not fit the existing expectations of what a cycle is and how itperforms. Current e-bike performance is limited principally bynormative legislative intervention, not by the intrinsic potential of thetechnologies. Existing decisions as to what an e-bike can (and should) be, areshaped by the performance expectations of late 19th and early 20thcentury bicycle designs. Shaping modal shift for longer trips returns us tothink about the place of cycling travel time as a function of the relationshipbetween distance and speed. Increased speed allows for greater distance withouttime penalty. However, speed is itself governed by available energy, coupledwith the efficiency of use of that energy. Without entirely substituting humanpower, E-motors allow us to augment the human power available in differentways; Changes in cycle design (as us, for example, in velomobiles) allow us toincrease the efficiency of use of available power in overcoming resistance tomovementIdentifying the assemblage of cycle/cyclist as avariable, rather than a determinate object to be accommodated, raises difficultquestions for cycling provision, especially in relation to longer distancetravel.This paper takes an approach rooted in Actor NetworkTheory and developed through social practice analysis to explore theinteractions of people machines and spaces for longer distance travel. It paysparticular attention to the capacities and affordances of each of theseelements, especially in their interaction. Drawing on the capacities of already existingtechnologies of cycling and e-cycling, the paper focuses on the socialimplications of potentially problematic interactions. It argues that newdecisions will need to be made in regard to speed and distance in cycle traveland that the forging of regulations consequent on those fundamentals  will substantially shape the potentials andpossibilities of modal shift for longer distance cycle travel. What emerges isa politics of longer distance cycle, not simply a set of technical barriers andproblems.

Book review: C. Popan (2019). Bicycle Utopias Imagining Fast and Slow Cycling Futures. Routledge.

Cosmin’s book ‘Bicycle Utopias:Imagining Fast and Slow Cycling Futures’ invites us to imagine a different world wherepredominantly bikes are used (at least) for short-distance travel within citiesand claims that the domination of cars is unsustainable and certainly notinevitable.  It also discusses the meritsof slow cycling and warns that the needs for speed and eternal economic growth arenot sustainable. He uses utopia as one of the methods to examine our commonlyheld beliefs and practices, along with auto-ethnography and other methods. Thisbook will certainly make the reader think, question their practices andpriorities, realize that today’s actions can shape the future, and that acar-centric world is not sustainable. A city dominated by slow cycling couldencourage the development of the local economy and small coops for cyclerepairs, deliveries, and generally helps create a virtuous cycle ofsustainable, sociable and healthy living.