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A. Nadi Najafabadi

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Journal article (2026) - Bahman Madadi, Ali Nadi, Gonçalo Homem de Almeida Correia, Thierry Verduijn, Lóránt Tavasszy
Teleoperated driving complements automated driving and acts as transitional technology towards full automation. An economic advantage of teleoperated driving in logistics operations lies in managing fleets with fewer teleoperators compared to vehicles with in-vehicle drivers. This alleviates growing truck driver shortage problems in the logistics industry and save costs. However, a trade-off exists between the teleoperator-to-vehicle (TO/V) ratio and the service level of teleoperation. This study designs a simulation framework to explore this trade-off generating multiple performance indicators as proxies for teleoperation service level. By applying the framework, we identify factors influencing the trade-off and optimal TO/V ratios under different scenarios. Our case study on road freight tours in the Netherlands reveals that for any operational settings, a TO/V ratio below one can manage all freight truck tours without delay, while one represents the current situation. The minimum TO/V ratio for zero-delay operations is never above 0.6, implying a minimum of 40% teleoperation labor cost saving. For operations where a small delay is allowed, TO/V ratios as low as 0.4 are shown to be feasible, which indicates potential savings of up to 60%. This confirms great promise for a positive business case for the teleoperated driving as a service. ...
As the rapid growth of urban e-commerce increases the volume of last-mile deliveries, logistics service providers have difficulty in meeting the demand of on-demand consumer requests. This increase in demand challenges traditional delivery, with some parcels becoming disproportionately costly to deliver to their destinations. To address this, we introduce a cost-based outlier parcel selection mechanism that identifies parcels with a high negative impact on the marginal delivery costs. These outlier parcels are then eliminated from their tours and outsourced to a crowdshipping market, where individuals combine the delivery task with their already planned trips. We use unique data on delivery tours of six service providers for the province of South Holland in the Netherlands. The cost-based decision rule for identifying outlier parcels results in a low proportion of outsourcing to the crowdshipping market compared to earlier literature. We identify only about 1 % of the total parcel demand as outliers across all carriers combined. Of these outlier parcels, the proportion selected for crowdshipping based on their cost efficiency ranges from 42.78 % to 3 %, depending on the scenario. While crowdshipping provides a viable solution for handling a small portion of last-mile deliveries, its environmental and economic sustainability is restricted by factors such as compensation rates and the delivery mode used. This study demonstrates that outsourcing high-cost outlier parcels to crowdshipping can be cost-efficient and reduce emissions of last-mile logistics companies; however, the proportion of these parcels is very small, limiting the overall impact on sustainability. ...
Journal article (2024) - Michiel de Bok, Lorant Tavasszy, Ali Nadi, Sebastiaan Thoen, Sofia Giasoumi, Jos Streng
City logistics simulation can help to provide empirical proof of potential benefits of new solutions in city logistics but decision support tools for such analyses are scarce because of a lack of empirical data and resources. The Tactical Freight Simulator (TFS) is a multi-agent simulator that represents the decision-making of freight agents and individual freight shipments. In this study it is applied to four distinct use cases in city logistics: micro hubs, introduction of zero-emission zones, crowd-shipping and the land use planning of logistic facilities. The simulations show impacts of each development and provide learnings: the type of open or single carrier operation of micro hubs have big local impacts. The impact of freight traffic avoiding zero emission zones can have substantial local impacts. Depending on the configuration of the service, crowd-shipping can lead to more vehicle kilometres. A common finding is the impact of the chosen scenario parameters on the outputs: regulation is important to shape city logistics operations. This also illustrates that, although the technology seems to be ready for innovative solutions, the logistical organisation or business models and policies are not yet well developed. ...
Journal article (2024) - Michiel de Bok, Sofia Giasoumi, Lori Tavasszy, Sebastiaan Thoen, Ali Nadi, Jos Streng
Micro-hubs are considered to be a potential solution to increase the consolidation of inner-city deliveries: in the City of Rotterdam it is a potential measure to increase the logistic efficiency in and around the planned zero-emission zone in the city center. When designing the configuration of micro-hubs in an urban setting multiple aspects should be considered, such as their location, the type of vehicles to operate them, and the business model to be adopted for their operation. And although the topic is much studied it remains difficult to predict how different micro-hub configurations affect the transportation system in terms of transport movements, number of travelled kilometers, etc. This paper describes the use of the Tactical Freight Simulator (TFS) to investigate the impact of micro-hubs on the transportation system in case they would be implemented at a wider scale across the city center, and make a comparison with the current state of last-mile delivery. The case study explores three different design aspects: location, type of vehicles (delivery robots, cargo bike, LEV), and the business model (individual/full collaboration). Results show that the largest reduction of vehicle kilometers can be achieved in the scenarios with full collaboration between the CEPs. ...
Crowdsourced shipping or crowdshipping is a promising contender for sustainable parcel delivery services due to the potential to consolidate freight trips with pre-existing passenger trips. However, the opportunity for private persons to act as occasional carrier can also generate new trips, which could then increase traffic volumes. Previous literature has focused on the consolidation case only, and has not addressed new activity generation in crowdshipping. In this study we investigate the willingness of private persons to accept shipments based on a newly generated home-based trip and compare this to choices of occasional carriers who had already planned their travel, in this case related to the daily commute. We conduct two stated preference experiments and apply a multinomial logit model to identify preferences. Additionally, a latent class choice model is utilized to explore the existence and effect of heterogeneity in preferences. The results show that commute-based and home-based trips have different VoT parameters and the former is higher than the latter. Parcel lockers as delivery points have a positive effect on acceptance since they allow for more flexibility in delivery times. The latent class model suggests that the distinction between low income and high-income groups is relevant; here, the low-income group has a lower value of time and is more willing to make a detour to execute the delivery. The study provides first quantitative evidence that crowdshipping can act as a potential trip generator in households and recommends that this is taken into account in passenger transportation models. ...
Conference paper (2023) - Michiel de Bok, Lóri Tavasszy, Ali Nadi, Raeed Mohammed
Goederenvervoer is het transport gedeelte van het logistieke systeem: goederen worden van A naar B vervoerd. Een groot gedeelte is onderdeel van logistieke ketens. Waar data over goederenvervoer in toenemende mate beschikbaar is voor onderzoek en planningsdoeleinden, blijft de beschikbaarheid van logistieke data schaars.
In deze bijdrage presenteren wij de resultaten van een data gedreven onderzoek waarbij ‘big’ tripdata van transporteurs zijn geanalyseerd op distributiestructuren. Uitdaging daarbij is de transport data te verrijken met logistieke informatie: vond deze rit plaats vanuit een multimodale terminal, een distributiecentra, of kwam deze vanaf een producent? Op de TU Delft hebben we een effectieve methode opgezet om structurele distributiepatronen te ontdekken, ondanks de data-inefficiënties.
De resultaten geven een relevante inkijk in distributiestructuren voor verschillende segmenten in het goederenvervoer: informatie die tot nog toe nog ontbreekt. ...
Journal article (2023) - Ali Nadi, Neil Yorke-Smith, Maaike Snelder, J. W.C. Van Lint, Lóránt Tavasszy
Understanding preferences and behaviours in road freight transport is valuable for planning and analysis. This paper proposes a data-driven vehicle routing and scheduling approach for use as a descriptive tool to study road freight transport activities. The model developed seeks to capture planners’ or drivers’ preferences in order to reproduce observed road freight activities. The model is based on a parametrized time-dependent vehicle routing problem whose parameters can be estimated from a set of observed planned tours. We propose a Bayesian optimization technique for parameter estimation of the model. Empirical results show that the model can fit real-world data accurately and synthesize tour flows close to reality. ...
Journal article (2023) - Raeed Ali Mohammed, Ali Nadi, Lórant Tavasszy, Michiel de Bok
Understanding the logistic determinants of freight trips is an important goal in freight transport modeling. Freight shipments move between nodes in the supply chain for different logistic purposes, including production, storage, transshipment, and consumption. A key problem with data availability is that databases generally do not identify these purposes, given the commercial sensitivity of the data. In addition, including information on senders and receivers of the shipments is often prohibitively costly. Therefore, one of the challenges of transport data analysis is to identify freight trip purposes using data fusion, linking information about the main function of logistics nodes to trips in existing databases. This paper proposes a data fusion approach to enrich big truck shipment databases with firm registry data. We use the national freight shipment micro-database from the Netherlands which includes shipment, vehicle, and tour information. Although our presentation here uses formats and methods of accounting for freight data used in the Netherlands, it can be readily replicated for conditions in other countries, as long as similar data sets on shipment data and firm registry are available. The enriched, new database contains transport and firm data for more than 2 million observed trips with information on the vehicle used, shipments carried, and sender/receiver firm. An initial descriptive analysis provides unique empirical insights into the logistic determinants of freight trips. These include the share of national trips that use intermediate nodes, typical changes in shipment sizes, and the role of distribution centers for (de)consolidation of shipments. ...
Journal article (2023) - Merve Seher Cebeci, Rodrigo Javier Tapia, Ali Nadi, Michiel de Bok, Lóránt Tavasszy
Crowdsourced shipping or crowdshipping is a promising solution to sustainable parcel delivery, owing to the potential to consolidate freight trips with preexisting passenger trips. Previous literature focuses on these consolidation benefits but does not address the possibility of new activity generation in crowdshipping. In this study, we investigate the willingness of private persons to accept shipments based on a newly generated home-based trip. We compare this to the choices of occasional carriers who build on the daily home–work commute to deliver parcels. Two stated preference experiments are conducted and a multinomial logit choice model and a latent class choice model are employed. These allow us to provide values of time of the occasional carriers, as an original contribution to the literature. The results show that commute-based carrier values of time are higher than those of home-based carriers. Concerning the trip generating power of crowdshipping, we find that low-income groups have a relatively high propensity to generate a home-based pickup and delivery trip. Finally, parcel lockers as delivery points positively influence acceptance of crowdshipping requests, as they allow for more flexibility in delivery times. Together, these results support the notion that crowdshipping can act as a potential trip generator in households. ...
Doctoral thesis (2022) - A. Nadi Najafabadi
This dissertation includes initial steps towards introducing a data-driven integrated logistics and traffic modelling framework. The main objective is to unravel the complex interaction between freight transport and traffic systems and to incorporate this knowledge into measures for improving the performance of traffic and logistics operations. Using large databases of observed truck trips and empirical research, a data-driven modelling pipeline is developed and applied, leading to new knowledge about the organization of road transport, in time and space. ...
Journal article (2022) - Ali Nadi, Alex Nugteren, Maaike Snelder, J. W.C.Van Lint, Jafar Rezaei
This paper introduces an advisory-based time slot management system (TSMS) to control truck arrivals at seaport terminals with the aim to reduce congestion at terminal gates. A modeling framework is proposed, developed, and applied to assess the impact of a truck arrival shift for a case study in the Port of Rotterdam. This system is designed to apply control policies on truck inflow while taking the behavioral aspect of truck operating companies (TOCs) into account. Discrete choice modeling is used to infer the time-of-day preferences of TOCs for container pick-ups from the exchange of information between port and hinterland stakeholders. These preferences are used to shift truck arrivals to the off-peak period which consequently reduces the high waiting time of trucks at terminals gates. To evaluate the effectiveness of the designed TSMS, a simulation platform that resembles terminal operations has been developed using discrete-event simulation. For the allocation of trucks to a certain time of day, a choice-based stochastic assignment heuristic is designed to approximate the optimum configuration of the truck arrival shift policy experiment. The optimum truck arrival shift design shows that significant gain can be obtained even at a low shift rate. ...
Journal article (2022) - Ali Nadi, Salil Sharma, J. W.C. van Lint, Lóránt Tavasszy, Maaike Snelder
This paper proposes a data-driven transport modeling framework to assess the impact of freight departure time shift policies. We develop and apply the framework around the case of the port of Rotterdam. Container transport demand data and traffic data from the surrounding network are used as inputs. The model is based on a graph convolutional deep neural network that predicts traffic volume, speed, and vehicle loss hours in the system with high accuracy. The model allows us to quantify the benefits of different degrees of adjustment of truck departure times towards the off-peak hours. In our case, travel time reductions over the network are possible up to 10%. Freight demand management can build on the model to design departure time advisory schemes or incentive schemes for peak avoidance by freight traffic. These measures may improve the reliability of road freight operations as well as overall traffic conditions on the network. ...
Journal article (2021) - Salil Sharma, Ioannis Papamichail, A. Nadi Najafabadi, Hans Van Lint, Lóránt Tavasszy, Maaike Snelder
Cooperative intelligent transportation systems (C-ITS) support the exchange of information between vehicles and infrastructure (V2I or I2V). This paper presents an in-vehicle C-ITS application to improve traffic efficiency around a merging section. This application balances the distribution of traffic over the available lanes of a freeway, by issuing targeted lane-changing advice to a selection of vehicles. We add to existing research by embedding multiple vehicle classes in the lane-changing advisory framework. We use a multi-class multi-lane macroscopic traffic flow model to design a feedback-feedforward control law that is based on a linear quadratic regulator (LQR). The performance of the proposed system is evaluated using a microscopic traffic simulator. The results indicate that the lane-changing advisory system is able to suppress Shockwaves in traffic flow and can significantly alleviate congestion. Besides bringing substantial travel time benefits around merging sections of up to nearly 21%, the system dramatically reduces the variance of travel time losses in the system. ...
Journal article (2021) - A. Nadi Najafabadi, Salil Sharma, Maaike Snelder, Taoufik Bakri, Hans van Lint, Lóránt Tavasszy
Short-term traffic prediction is an important component of traffic management systems. Around logistics hubs such as seaports, truck flows can have a major impact on the surrounding motorways. Hence, their prediction is important to help manage traffic operations. However, The link between short-term dynamics of logistics activities and the generation of truck traffic has not yet been properly explored. This paper aims to develop a model that predicts short-term changes in truck volumes, generated from major container terminals in maritime ports. We develop, test, and demonstrate the model for the port of Rotterdam. Our input data are derived from exchanges of operational logistics messages between terminal operators, carriers and shippers, via the local Port Community System. We propose a feed-forward neural network to predict the next one hour of outbound truck traffic. To extract hidden features from the input data and select a model with appropriate features, we employ an evolutionary algorithm in accordance with the neural network model. Our model predicts outbound truck volumes with high accuracy. We formulate 2 scenarios to evaluate the forecasting abilities of the model. The model predicts lag and non-proportional responses of truck flows to changes in container turnover at terminals. The findings are relevant for traffic management agencies to help improve the efficiency and reliability of transport networks, in particular around major freight hubs. ...
Journal article (2021) - Salil Sharma, Ioannis Papamichail, Ali Nadi, Hans van Lint, Lorant Tavasszy, Maaike Snelder
Cooperative intelligent transportation systems (C-ITS) support the exchange of information between vehicles and infrastructure (V2I or I2V). This paper presents an in-vehicle C-ITS application to improve traffic efficiency around a merging section. The application balances the distribution of traffic over the available lanes of a freeway, by issuing targeted lane-changing advice to a selection of vehicles. We add to existing research by embedding multiple vehicle classes in the lane-changing advisory framework. We use a multi-class multi-lane macroscopic traffic flow model to design a feedback-feedforward control law that is based on a linear quadratic regulator (LQR). The weights of the LQR controller are fine-tuned using a response surface method. The performance of the proposed system is evaluated using a microscopic traffic simulator. The results indicate that the multi-class lane-changing advisory system is able to suppress shockwaves in traffic flow and can significantly alleviate congestion. Besides bringing substantial travel time benefits around merging sections of up to nearly 21%, the system dramatically reduces the variance of travel time losses in the system. The proposed system also seems to improve travel times for mainline and ramp vehicles by nearly 20% and 42%, respectively. ...
Conference paper (2020) - Ali Nadi , Hans van Lint, Lorant Tavasszy, Maaike Snelder
Scheduling and Routing in freight transport are usually the end products of an optimization process. However, the results may differ due to the heterogeneity of rules in different transport markets. Since the understanding of these decision rules is important for disaggregate freight modeling, this paper investigates the development of an effective decision tree method for extracting them from an extensive freight transport data. We applied the method to model departure time and type of tours in freight transport of agricultural products. Having these two models together help us understand the whole anatomy of the freight activities for the selected transport segment. The models highlight the characteristics of time-of-day freight activities for this sector and indicate the importance of spatial and temporal characteristics in capturing the distinctions of the type of tours. ...
In gateway seaports, like the port of Rotterdam, a substantial proportion of all freight movements is related to trips to hinterland markets. Accordingly, outbound truck flows from port areas, especially in traffic rush-hours, may degrade the level of service on truck-dominated motorways or increase the unreliability of freight transport operation. Therefore, these truck flows during traffic rush hours are of particular interest to both port and road transport authorities.Consequently, the main objective of this paper is to identify key features of port activities that induce truck traffic during rush hours by using both terminal activity data, at the container level, and truck-specific counts obtained from loop detector data for the year 2015. In this paper, we focus on inbound/outbound truck traffic. From our analysis, we find that terminals operational attributes such as estimated pick up time and container discharge time contribute mostly to the rush hour truck traffic. Besides, we identify the vessel attributes (call size), container features (size and type), and commodities which brings inefficiencies in the traffic system. Our research would be of interest to traffic managers, port of authority, and freight forwarders to invest in interventions which could improve the reliability of road freight operations. ...