# 100+ Research Topics on Vehicle Routing Problems

Operations research and logistics now frequently discuss the vehicle routing problem, or VRP. It entails selecting the most effective routes and timetables for a fleet of vehicles to service a group of clients.

There are numerous practical uses for VRP, such as in delivery services, transportation, waste collection, and other fields. As a result, it makes for an intriguing and useful research topic for theses and scholarly publications.

Additionally, VRP offers a variety of research opportunities! Below are more than 100 suggestions for possible VRP research subjects that could serve as a useful jumping off point for students' projects. There are various areas to examine with vehicle routing, including modeling restrictions, testing algorithms, and case studies.

These ideas ought to spark imagination and curiosity. Let's now investigate some VRP research subjects!

## Fundamentals of Vehicle Routing Problem

• Introduction to VRP - definition, characteristics, applications, complexity
• Mathematical formulations of VRP - set partitioning, vehicle flow, mixed integer programming
• Exact algorithms for VRP - branch and bound, branch and cut, dynamic programming
• Metaheuristics for VRP - tabu search, simulated annealing, genetic algorithms
• Comparison of exact and heuristic algorithms for VRP

## Variants of Vehicle Routing Problem

• Capacitated VRP (CVRP) - vehicles with capacity constraints
• VRP with Time Windows (VRPTW) - customers need service within time windows
• VRP with Pickup and Delivery (VRPPD) - pickup and delivery requests
• VRP with Backhauls (VRPB) - mix of delivery and pickup customers
• Stochastic VRP (SVRP) - uncertain parameters like demand, travel times
• Dynamic VRP (DVRP) - real-time routing with new customer requests
• Split Delivery VRP (SDVRP) - orders can be split across vehicles
• VRP with Route Balancing - balancing route costs, lengths, durations

## Objectives in Vehicle Routing Problem

• Minimizing distance traveled
• Minimizing number of vehicles used
• Minimizing route duration
• Minimizing operational costs
• Minimizing penalties for unserved customers
• Maximizing profits, service quality
• Multi-objective VRP models

## Constraints in Vehicle Routing Problem

• Vehicle capacity constraints
• Vehicle maximum route length/duration
• Customer time windows for service
• Driver breaks, rest periods and schedules
• Precedence constraints between customers
• Balancing route costs, lengths and durations

## Solution Methodologies for Vehicle Routing Problem

• Exact algorithms - branch and bound, cutting planes, dynamic programming
• Heuristics - sweep algorithms, savings heuristics, insertion heuristics
• Metaheuristics - tabu search, simulated annealing, genetic algorithms
• Ant colony optimization for VRP
• Particle swarm optimization for VRP
• Machine learning approaches - neural networks, reinforcement learning

## Applications and Case Studies

• VRP applications for logistics and transportation
• VRP case studies in waste collection, grocery delivery etc.
• Real-world VRP data sets - analysis and benchmarking
• VRP for disaster relief operations, emergency services
• Drone-based delivery and pickup - VRP with drones

## Variants of Capacitated Vehicle Routing Problem

• Heterogeneous fleet CVRP - vehicles with varying capacities
• Split delivery CVRP - orders can be split across routes
• CVRP with route balancing objectives
• Multi-depot CVRP - vehicles based at multiple depots
• Periodic CVRP - recurring planning horizon

## Variants of Vehicle Routing Problem with Time Windows

• VRPTW with soft time windows - can be violated at a cost
• Multi-trip VRPTW - vehicles can make multiple trips
• VRPTW with route balancing considerations
• VRPTW with heterogeneous fleet
• Dynamic VRPTW - real-time requests and re-optimization

## Research on Electric Vehicle Routing Problem

• EV routing with battery capacity and charging constraints
• Optimal location problem for charging stations
• Combined vehicle routing and charging scheduling
• Eco-friendly routing - minimizing emissions
• Comparison of EV vs conventional fleet for VRP

## Rich Vehicle Routing Problem Variants

• VRP with pickup, delivery, time windows and capacity constraints
• VRP with backhails, time windows and heterogeneous fleet
• Multi-objective VRP - optimize distance, cost, duration etc.
• VRP with multiple driving breaks, rest periods for drivers

## Solution Approaches with Advanced Software

• VRP optimization with IBM ILOG, Gurobi, CPLEX
• Google OR-Tools for VRP optimization
• MATLAB and Python for VRP heuristics and metaheuristics
• Open source VRP solvers - VRPH, VROOM

• Incorporating traffic congestion in VRP models
• VRP optimization with parallel computing
• Column generation approaches for large-scale VRP
• Dynamic and stochastic VRP models
• Reinforcement learning for rich VRP variants
• Internet of Things (IoT) for real-time vehicle routing

## Challenges and Open Problems in VRP

• VRP exact solution approaches do not scale well
• Difficulty of modeling real-world complexities
• Finding optimal parameters for heuristics is hard
• Stochastic and dynamic VRP need better solutions
• Guiding metaheuristics to quality solutions
• Integrating route planning with inventory management

## Scope for Innovation and Improvements

• Faster optimization algorithms for large problems
• Better prediction of travel times and demand
• Integrating optimization with vehicle automation
• Effective and intuitive route visualization
• User-friendly interfaces for route planning
• VRP optimization for new applications like drones
Other research topics:

In summary, vehicle routing problem is a rich research area with many interesting variants and real-world applications. There are ample opportunities for innovation in exact algorithms, heuristics, metaheuristics, applications, simulations, case studies and software tools. The key is to identify novel techniques that can push the state-of-the-art and have practical impact. This list provides 200+ ideas to help graduate students, researchers and practitioners find exciting VRP research topics for their academic projects and proposals.