Fraser McLeod

Transport impacts of local collection/delivery points

This paper presents an analysis of the vehicle mileage incurred by carriers and customers using local collection/delivery points (CDPs) for failed first time home shopping deliveries compared with the traditional carrier redelivery method. A number of key factors were identified, including the delivery failure rate, the carrier depot distance from the delivery area, the number of available collection points, the preferred modes of transport used by householders and the extent to which trips were combined with each other. The results of a case study using CDPs in the city of Winchester, UK, indicated that customer mileage could be reduced by over 80%, while the estimated impact on carrier mileage was negligible. Worst-case and best-case scenarios for the collection point delivery method were also modelled, which demonstrated that overall mileage could be reduced by 80% or increased by 40% depending on the assumptions made about the key factors.

Loading bay booking and control for urban freight

This paper investigates the concept of a loading bay advance booking and control system for delivery and service vehicle drivers. A case study of Winchester High Street is presented to illustrate the potential impact of such a system. A number of operating scenarios were considered based on the punctuality of deliveries and service visits, using a comprehensive database of vehicle arrival patterns. The main performance measures used were adherence to schedule, delivery time and the use of unloading points, with reference to their desirability, both from the freight vehicle drivers’ and other road users’ viewpoints. The research has highlighted the different factors that would need to be taken into account when evaluating a managed loading bay system, from the standpoints of the various actors involved, including the traffic authority, freight operator, driver, retailer and other road users.

Assessing the long-term performance of cross-sectoral strategies for national infrastructure

National infrastructure systems (energy, transport, digital communications, water, and waste) provide essential services to society. Although for the most part these systems developed in a piecemeal way, they are now an integrated and highly interdependent “system of systems.” However, understanding the long-term performance trajectory of national infrastructure has proved to be very difficult because of the complexity of these systems (in physical and institutional terms) and because there is little tradition of thinking cross-sectorally about infrastructure system performance. Here, a methodology is proposed for analyzing national multisectoral infrastructure systems performance in the context of uncertain futures, incorporating interdependencies in demand across sectors. Three contrasting strategies are considered for infrastructure provision (capacity intensive, capacity constrained, and decentralized) and multiattribute performance metrics are analyzed in the context of low, medium, and high demographic and economic growth scenarios. The approach is illustrated using Great Britain and provides the basis for the development and testing of long-term strategies for national infrastructure provision. It is especially applicable to mature industrial economics with a large stock of existing infrastructure and challenges of future infrastructure provision.

Estimating bus passenger waiting times from incomplete bus arrivals data

This paper considers the problem of estimating bus passenger waiting times at bus stops using incomplete bus arrivals data. This is of importance to bus operators and regulators as passenger waiting time is a key performance measure. Average waiting times are usually estimated from bus headways, that is, time gaps between buses. It is both time-consuming and expensive to measure bus arrival times manually so methods using automatic vehicle location systems are attractive; however, these systems do not usually provide 100% data coverage and missing data are problematical. The paper contributes to the general theory of estimating headway variance using incomplete data. Various methods for replacing missing buses or discarding spurious bus headways are compared and tested on different data sets.

Carbon Dioxide Benefits of Using Collection-Delivery Points for Failed Home Deliveries in the United Kingdom

Unlike much of the previous research on this topic, which assesses the economic consequences of failed deliveries to the home, this study examines the issue of failed delivery from a carbon-auditing perspective. It considers the potential environmental savings from the use of alternative forms of collection and delivery over traditional delivery methods for failed home deliveries. With a spreadsheet carbon audit model, carbon dioxide (CO2) emissions for a failed delivery are calculated on the basis of a typical van home delivery round of 120 drops and 50-mi (80-km) distance. Three first-time delivery failure rates (10%, 30%, and 50%) are assessed. The additional CO2 from a second delivery attempt increases the emissions per drop by 9% to 75% (depending on the delivery failure rate). The vast majority (85% to 95%) of emissions emanating from a traditional failed delivery arise not from the repeat van delivery but from the personal travel associated with the customers collecting a missed redelivery from the carriers local depot. A range of collection–delivery points (CDPs) (supermarkets, post offices, railway stations) were all found to reduce the environmental impact of this personal travel. Post offices (currently operating a CDP system through the U.K. Royal Mails Local Collect service) yielded the greatest savings, creating just 13% of the CO2 produced by a traditional collection by car from a local depot. Overall, the research suggests that the use of CDPs offers a convenient and more environmentally friendly alternative to redelivery and customer collection from a local parcel depot.

Enabling the freight traffic controller for collaborative multi-drop urban logistics: practical and theoretical challenges

There is increasing interest in how horizontal collaboration between parcel carriers might help alleviate problems associated with last-mile logistics in congested urban centers. Through a detailed review of the literature on parcel logistics pertaining to collaboration, along with practical insights from carriers operating in the United Kingdom, this paper examines the challenges that will be faced in optimizing multi-carrier, multidrop collection, and delivery schedules. A “freight traffic controller” (FTC) concept is proposed. The FTC would be a trusted third party, assigned to equitably manage the work allocation between collaborating carriers and the passage of vehicles over the last mile when joint benefits to the parties could be achieved. Creating this FTC concept required a combinatorial optimization approach for evaluation of the many combinations of hub locations, network configuration, and routing options for vehicle or walking to find the true value of each potential collaboration. At the same time, the traffic, social, and environmental impacts of these activities had to be considered. Cooperative game theory is a way to investigate the formation of collaborations (or coalitions), and the analysis used in this study identified a significant shortfall in current applications of this theory to last-mile parcel logistics. Application of theory to urban freight logistics has, thus far, failed to account for critical concerns including (a) the mismatch of vehicle parking locations relative to actual delivery addresses; (b) the combination of deliveries with collections, requests for the latter often being received in real time during the round; and (c) the variability in travel times and route options attributable to traffic and road network conditions.

Bus Priority at Traffic Signals—Evaluating Strategy Options

This article compares different strategy options for providing bus priority at traffic signals. The different strategies considered vary in the strength of the priority awarded and in the selection of the buses that are to receive priority. The strategies include so-called differential priority, where buses receive individual priority treatment according to some criterion such as lateness, and nondifferential priority, where all buses are treated in the same way. The strategies are compared using a simulation model, SPLIT, that has been developed and validated. The article describes some of the modelling issues that are involved in simulating bus priority systems and how they have been treated with the SPLIT model.

AUTOMATIC VEHICLE LOCATION: IMPLEMENTATION, APPLICATION, AND BENEFITS IN THE UNITED KINGDOM

Automatic vehicle location (AVL) is playing an increasingly important role in public transport operations in the United Kingdom, providing support for real-time management and control of bus fleets and the platform for other beneficial functions including passenger information systems and bus priority. The current and emerging use of AVL in the United Kingdom for public transport is considered in this paper, focusing in particular on developments in London and Southampton where substantial use is being made of AVL. Following a summary description of AVL systems and technologies, examples are presented of the use of AVL for real-time passenger information at bus stops, particularly the COUNTDOWN and STOPWATCH systems in London and Southampton, respectively. Technical aspects are described together with evaluation results including passenger attitudes and financial criteria. Positive results in both cities have led to commitments for citywide implementations. The use of AVL in applications for bus priority at traffic signals is described, including a comparative review of different architectures and techniques that have emerged. Results of a feasibility study for the use of AVL in this context in London are presented. This study indicated that using AVL to target high-occupancy, high-headway buses with higher levels of priority could provide economic benefits for buses and passengers up to twice those achieved with current operations, where priority is equally available to all buses. Deployment details of this application, related to COUNTDOWN, are described. The paper concludes with the outlook for AVL, particularly for greater integration with traffic control systems, where significant potential benefits are outlined.

Dynamic collection scheduling using remote asset monitoring

Remote sensing technology is now coming onto the market in the waste collection sector. This technology allows waste and recycling receptacles to report their fill levels at regular intervals. This reporting enables collection schedules to be optimized dynamically to meet true servicing needs in a better way and so reduce transport costs and ensure that visits to clients are made in a timely fashion. This paper describes a real-life logistics problem faced by a leading UK charity that services its textile and book donation banks and its high street stores by using a common fleet of vehicles with various carrying capacities. Use of a common fleet gives rise to a vehicle routing problem in which visits to stores are on fixed days of the week with time window constraints and visits to banks (fitted with remote fill-monitoring technology) are made in a timely fashion so that the banks do not become full before collection. A tabu search algorithm was developed to provide vehicle routes for the next day of operation on the basis of the maximization of profit. A longer look-ahead period was not considered because donation rates to banks are highly variable. The algorithm included parameters that specified the minimum fill level (e.g., 50%) required to allow a visit to a bank and a penalty function used to encourage visits to banks that are becoming full. The results showed that the algorithm significantly reduced visits to banks and increased profit by up to 2.4%, with the best performance obtained when the donation rates were more variable.

A NEURAL NETWORK MODEL FOR ENHANCED OPERATION OF MIDBLOCK SIGNALLED PEDESTRIAN CROSSINGS

UK transport policy has shifted dramatically in recent years. The new policy direction to promote walking as an alternative to car for short trips. Midblock signalled pedestrian crossings are a common method of resolving the conflict between pedestrians and vehicles. This paper considers alternative operating strategies for midblock signalled pedestrian crossings that are more responsive to the needs of pedestrians without increasing the delay to motorists and freight traffic. A succession of artificial neural network (ANN) models is developed and factors influencing the performance of pedestrian gap acceptance models both in terms of accuracy and processing requirements are considered in detail. The paper concludes that a feedforward ANN using backpropagation can deliver a gap acceptance model with a high degree of accuracy with acceptable constraints.