Multimodal Transportation Systems

Chapter 15
Multimodal Strategy and Future Transport Systems

Post Graduate Program in Logistics
Multimodal Transportation Systems   •   Post Graduate

Multimodal Strategy and Future Transport Systems

Introduction

Multimodal transportation strategy concerns the coordinated design and governance of transport services that use two or more modes—such as road, rail, inland waterway, maritime shipping, air freight and pipelines—within one logistics system. The strategic problem is not simply to select the cheapest mode. It is to configure a network that balances cost, transit time, reliability, resilience, emissions, service quality, regulatory compliance and long-term adaptability.

Contemporary logistics is being reshaped by e-commerce, geopolitical uncertainty, climate policy, urban restrictions, digital platforms, labour shortages, automation and the need to decarbonise freight. These pressures have encouraged the development of synchromodality, the Physical Internet, green corridors, platform-based logistics and autonomous transport systems. Each promises greater flexibility and efficiency, but each also creates new requirements for data governance, investment, institutional coordination and risk management.

A sound multimodal strategy therefore integrates four decisions:

  1. Network decisions: where facilities, terminals, corridors and services should be located.
  2. Commercial decisions: how services are priced, contracted, coordinated and sold.
  3. Technology decisions: how data, automation, artificial intelligence and digital platforms support operations.
  4. Sustainability and governance decisions: how environmental, social, safety and regulatory objectives are incorporated.

The central managerial challenge is to avoid treating these decisions independently. A technically advanced system can fail commercially; a low-emission route can be unreliable; and a highly efficient network can become vulnerable when it lacks alternatives.

Learning Objectives

After studying this chapter, the learner should be able to:

  • formulate an integrated multimodal transport strategy;
  • distinguish multimodality, intermodality, combined transport and synchromodality;
  • evaluate network, commercial, technological and sustainability trade-offs;
  • explain the principles and limitations of the Physical Internet;
  • assess green corridors and platform business models;
  • analyse autonomous and connected transport systems;
  • apply a structured framework to future policy and investment scenarios; and
  • identify governance, ethical, cybersecurity and implementation risks.

1. Strategic Architecture of a Multimodal System

1.1 From mode selection to system design

Traditional mode choice often compares road, rail, water and air using freight rate and transit time. Strategic multimodal design is broader. It considers the complete door-to-door chain, including first-mile collection, terminal handling, line-haul movement, customs, storage, last-mile delivery, information exchange and contingency arrangements.

A useful objective is to minimise total logistics cost while satisfying service and policy constraints. In general form:

Minimise Z = Ctransport + Chandling + Cinventory + Cdelay + Cexternality

Here, Z is total evaluated system cost; Ctransport is transport cost; Chandling is terminal and transfer cost; Cinventory is the cost of goods held in transit or safety stock; Cdelay is the expected cost of lateness and disruption; and Cexternality represents monetised environmental or social impacts. The expression is a strategic evaluation framework rather than a universal accounting identity. The terms must be defined consistently, and externalities should not be added when they are already embedded in market prices or regulatory charges.

Subject to:

  • demand being served;
  • capacity and compatibility constraints being respected;
  • safety and legal requirements being met;
  • agreed delivery windows being achieved; and
  • budget, carbon or resilience targets being satisfied.

The relevant comparison is total landed logistics performance, not the line-haul rate of one mode.

1.2 Network configuration

A multimodal network consists of nodes and links. Nodes include suppliers, distribution centres, ports, rail terminals, airports, consolidation centres and customers. Links represent transport services or information flows. Important strategic choices include:

  • hub concentration versus decentralisation: concentration can exploit scale economies, while decentralisation can reduce vulnerability and delivery distance;
  • direct services versus transshipment: direct services reduce handling but may operate less frequently;
  • dedicated versus shared capacity: dedicated capacity offers control, whereas shared capacity can improve utilisation;
  • centralised versus distributed inventory: centralisation may lower stock duplication but increase distance and disruption exposure; and
  • single sourcing versus portfolio sourcing: multiple routes and carriers improve resilience but may raise coordination cost.

A network should be evaluated under both normal and disrupted conditions. A route with the lowest expected cost may not be best if a port closure, flood, cyberattack or labour stoppage causes unacceptable losses.

1.3 Service attributes and total logistics value

Customers generally value a bundle of attributes:

AttributeStrategic question
CostWhat is the total cost per shipment or unit?
SpeedCan the delivery promise be met?
ReliabilityHow variable is transit time?
FlexibilityCan volume, route or mode be changed?
VisibilityCan shipment status and condition be observed?
SustainabilityWhat emissions and social impacts are created?
ResilienceCan the system recover from disruption?

Reliability is especially important in multimodal chains because delays can propagate at transfer points. If one service arrives after the planned connection, the shipment may incur waiting, storage, missed sailing or expedited transport costs.

2. Multimodality, Intermodality and Synchromodality

Multimodality means that two or more transport modes are used in a journey. The modes may be managed separately under different contracts.

Intermodality generally refers to the movement of goods in the same loading unit or vehicle body across different modes, with the goods themselves not being handled during transfer. A container moved by truck, rail and ship is a common example.

Combined transport is a form of intermodal transport in which the main leg uses rail, inland waterway or short-sea shipping and the initial and final legs are relatively short by road. Exact legal definitions vary by jurisdiction.

Synchromodality extends these concepts by allowing the mode or route to be selected dynamically according to real-time conditions, available capacity, customer requirements and network status. The customer purchases a transport outcome—such as delivery by a specified time—rather than necessarily prescribing one fixed mode.

2.1 Conditions for synchromodality

Synchromodality requires more than a tracking application. Its foundations include:

  • a network with genuinely substitutable modes;
  • interoperable digital information;
  • visibility of capacity, schedules and disruptions;
  • contractual permission to change mode or route;
  • standardised loading units and handling processes;
  • decision rules for cost, service and emissions; and
  • trust among shippers, carriers, terminals and authorities.

A practical decision hierarchy may prioritise mandatory constraints first, followed by service, cost, emissions and resilience. For example, a refrigerated pharmaceutical shipment may require temperature integrity and a delivery window before cost optimisation is considered.

2.2 Dynamic mode choice

A simple expected-cost comparison for two feasible alternatives is:

E(Ci) = Ci + pi Li + ei Pe

E(Ci) is the evaluated expected cost of option i, in monetary units; Ci is direct and handling cost; pi is the probability of a disruption or service failure; Li is the resulting loss; ei is emissions, measured for example in kilograms of CO₂-equivalent; and Pe is the chosen carbon price per kilogram. The formula assumes that the disruption loss and carbon price are represented in comparable monetary units and that risk is adequately represented by an expected-value approximation. It does not capture severe low-probability events well; scenario analysis is needed for those cases.

Synchromodal control may select the option with the lowest E(Ci) subject to delivery and safety constraints. In practice, a multi-objective model or managerial rule may be preferable because cost, emissions and resilience are not always commensurable.

3. The Physical Internet

The Physical Internet is a conceptual vision for an open, interconnected logistics system in which goods move through shared networks using modular, standardised and digitally identifiable containers. It draws an analogy with the Digital Internet: standard protocols allow independent networks to interconnect and route information, while Physical Internet proposals seek interoperable logistics hubs, services and modular packages.

Its principal design ideas are:

  • modularity: goods are packed in standard reusable π-containers or compatible units;
  • encapsulation: products are protected and grouped into handling units;
  • routing and switching: units can be dynamically directed through available nodes;
  • open hubs: freight may transfer between organisations using common standards;
  • real-time visibility: digital identities and event data support routing; and
  • network sharing: capacity is pooled rather than reserved entirely for individual firms.

The potential benefits include higher vehicle and terminal utilisation, fewer empty movements, greater consolidation, improved resilience and lower emissions. However, the Physical Internet is not merely a technology project. It requires commercial openness, liability rules, common data standards, investment in compatible equipment and agreement on service quality.

Important limitations include the cost of repackaging, product-specific handling requirements, loss of direct control, data-sharing reluctance, congestion at popular hubs and the possibility that additional transfers increase damage or delay. The concept is therefore best understood as a long-term operating architecture rather than a claim that all freight should pass through shared networks.

4. Green Corridors and Sustainable Strategy

A green corridor is a freight route or logistics ecosystem in which public and private actors coordinate to accelerate the adoption of low- and zero-emission technologies. A corridor may link ports, industrial regions, inland terminals and cities. Its success depends on aligned infrastructure, vehicle and vessel technology, energy supply, regulation, finance and demand.

Typical interventions include:

  • electrified rail and terminal equipment;
  • shore-side electricity for vessels;
  • renewable electricity and alternative fuels;
  • hydrogen or battery charging infrastructure where operationally suitable;
  • priority access or differentiated fees for cleaner vehicles;
  • digital monitoring of emissions and congestion;
  • harmonised customs and safety procedures; and
  • long-term cargo commitments that reduce investment risk.

4.1 Measuring emissions

For a transport leg, a basic activity-based estimate is:

E = D × M × EF

E is emissions, usually in kilograms of CO₂-equivalent; D is distance in kilometres; M is transported mass in tonnes; and EF is the emission factor in kilograms of CO₂-equivalent per tonne-kilometre. The units are consistent because km × tonnes × kg CO₂e/(tonne-km) = kg CO₂e. The method assumes that the emission factor is appropriate for the mode, vehicle, fuel, load factor and accounting boundary. Empty repositioning, terminal energy and well-to-wheel emissions must be included when the chosen reporting standard requires them.

For a multimodal shipment, leg emissions are added:

Etotal = ∑ Ej

where Ej is emissions from leg j. Comparisons must use the same shipment mass, distance basis, allocation rule and system boundary. A mode with low tailpipe emissions may still have substantial upstream emissions if its energy source is carbon intensive.

Sustainability strategy should also address noise, land use, congestion, worker safety, labour conditions, local air pollution and equity. Decarbonisation is not automatically socially neutral: charging infrastructure, new terminals and route changes distribute costs and benefits unevenly.

5. Platform Business Models and Digital Coordination

Digital freight platforms connect shippers, carriers, terminals, brokers, financiers and sometimes regulators. They may provide quotation, booking, capacity matching, tracking, documentation, payment, insurance and performance analytics.

A platform business model creates value through interaction among participant groups. It may earn revenue through transaction fees, subscriptions, data services, financing margins or value-added logistics services. Its strategic advantage can arise from network effects: as more verified carriers join, the platform becomes more useful to shippers, and vice versa.

However, network effects do not guarantee success. A platform must solve the initial “chicken-and-egg” problem, maintain data quality, prevent discriminatory access, protect commercially sensitive information and establish clear liability for incorrect bookings or fraudulent status events.

5.1 Data architecture and AI

A credible multimodal platform should distinguish:

  • master data, such as locations, equipment and product identifiers;
  • transactional data, such as bookings and invoices;
  • event data, such as departure, arrival and transfer scans;
  • sensor data, such as temperature, shock and location; and
  • analytical outputs, such as predicted arrival time or disruption alerts.

Artificial intelligence can support demand forecasting, ETA prediction, document classification, capacity matching, predictive maintenance and disruption detection. Yet AI predictions are only as reliable as their data, assumptions and operating context. Models can become inaccurate after a route change, extreme weather event or new regulatory regime. Human oversight remains necessary for safety-critical decisions, exceptional cargo and legally consequential actions.

Best practice includes data provenance, role-based access, cybersecurity controls, model monitoring, explainability appropriate to the decision and a documented process for challenging automated outputs.

6. Autonomous and Connected Transport Systems

Autonomous transport ranges from driver assistance to highly automated operation. Relevant applications include automated guided vehicles in terminals, autonomous yard tractors, warehouse robots, remotely supervised vessels, automated trains and delivery drones. Connected systems use vehicle-to-vehicle, vehicle-to-infrastructure and vehicle-to-network communication to improve coordination.

Potential benefits include improved safety, continuous operation, lower labour exposure to hazardous tasks, better fuel efficiency and more predictable capacity. Risks include software failure, sensor limitations, cyberattack, unclear responsibility, workforce displacement and interactions with conventional vehicles and pedestrians.

Deployment should be staged. A sensible sequence is:

  1. controlled environments, such as fenced yards;
  2. supervised operation on defined corridors;
  3. limited mixed-traffic deployment;
  4. network-wide integration after safety evidence and regulatory approval.

Safety cases should identify hazards, failure modes, fallback procedures and responsible human operators. Automation should not be evaluated only by labour-cost reduction. Reliability, maintenance, training, cybersecurity, insurance and social consequences must be included in the business case.

7. Policy and Scenario Planning

Future transport systems are uncertain because technology, energy prices, trade patterns, regulation and public preferences may change together. Forecasting one “most likely” future can create false confidence. Scenario planning is more appropriate when uncertainty is deep.

Useful scenario dimensions include:

  • open versus fragmented trade;
  • rapid versus slow decarbonisation;
  • high versus low automation adoption;
  • abundant versus constrained energy;
  • strong versus weak data interoperability; and
  • centralised versus distributed production.

A scenario does not predict the future. It tests whether a strategy remains robust under different conditions. A strategy is more robust when it performs acceptably across several plausible scenarios, even if it is not optimal in one forecast.

Policy instruments may include emissions standards, carbon pricing, infrastructure subsidies, public procurement, road pricing, access restrictions, interoperability mandates, safety regulation, data protection and competition law. Policymakers must consider unintended effects. For example, a road restriction may shift freight to rail, but if rail capacity is unavailable it may simply create congestion elsewhere or raise prices for smaller firms.

8. Integrated Strategic Framework

A practical strategy process can be organised into seven stages:

Stage 1: Define objectives and service segments

Segment freight by urgency, value, temperature sensitivity, hazard, volume, regularity and customer promise. A single network policy is rarely suitable for all products.

Stage 2: Map the end-to-end network

Record nodes, links, transfer points, contracts, information flows, capacity constraints and dependencies. Include informal workarounds that operators use during disruption.

Stage 3: Establish a baseline

Measure cost, transit time, variability, damage, emissions, asset utilisation, empty running, incidents and customer outcomes. Baseline data should use consistent definitions.

Stage 4: Design alternatives

Develop options such as rail substitution, inland waterway use, consolidation, regional inventory, alternative ports, shared platforms or green-corridor participation.

Stage 5: Test normal and disrupted conditions

Use sensitivity analysis and scenarios for fuel price, demand, capacity, weather, border delay, cyberattack and infrastructure failure.

Stage 6: Build the commercial and governance model

Define ownership, access rights, tariffs, service-level agreements, data responsibilities, liability, dispute resolution and investment commitments.

Stage 7: Pilot, measure and scale

Start with a bounded corridor or commodity flow. Use measurable targets, independent evaluation and a mechanism for revising the design.

A balanced scorecard may combine financial, service, environmental, resilience and social indicators. Metrics should not be optimised in isolation. For example, maximum vehicle utilisation could increase waiting time and reduce customer service.

9. Illustrative Case: The Northstar Regional Freight Corridor

This is a fictional illustrative case designed for academic application.

Background

Northstar is a manufacturing region served by a seaport 420 km from an inland distribution centre. Most containers move entirely by road. The route is congested, emissions are rising and customers increasingly request lower-carbon delivery. A rail service exists but is infrequent and has limited terminal capacity.

Problem

The logistics consortium must reduce emissions by at least 25% within five years while maintaining delivery within 48 hours for standard freight. It must also preserve an alternative route because the port is exposed to storm disruption.

Analysis

The consortium maps demand by day, product class and customer promise. Standard freight can tolerate a scheduled rail leg, while urgent and temperature-sensitive freight requires greater flexibility. The analysis identifies three options:

  • road-only delivery, with high flexibility and high emissions;
  • scheduled rail plus road drayage, with lower emissions but transfer risk; and
  • a synchromodal portfolio using rail, road and a secondary port during disruption.

The consortium calculates emissions using E = D × M × EF for each leg, ensuring that distances, mass and emission factors use the same boundary. It also estimates expected delay cost and tests port-closure scenarios.

Approach and solution

The parties establish a corridor platform with shared booking and event standards. The customer contract specifies a 48-hour delivery window and maximum carbon intensity rather than a mandatory mode. Rail receives the predictable base volume; road carriers provide surge capacity; and a secondary port is prequalified for disruption. Terminal operating hours are synchronised, and a common exception process authorises mode changes.

A governance board comprising shippers, carriers, terminals, the port authority and public agencies sets data access rules and reviews performance monthly. The pilot begins with one commodity group and excludes hazardous goods until safety and liability procedures are validated.

Outcome

In the illustrative outcome, the corridor achieves the emissions target for participating freight, improves visibility and reduces dependence on the primary port. However, the business case shows that rail is not cheaper for every shipment. Benefits depend on reliable terminal slots, sufficient base volume and transparent treatment of waiting and drayage costs.

Learning points

  1. A green corridor requires coordinated demand, infrastructure and governance.
  2. Synchromodality is credible only when alternative capacity is contractually and operationally available.
  3. Emission reduction should be evaluated with a defined accounting boundary.
  4. Resilience may justify maintaining a higher-cost alternative.
  5. Pilots should be segmented by cargo characteristics rather than applied indiscriminately.

10. Challenges, Ethics and Governance

Future multimodal systems create several governance questions.

Data ownership and privacy: Shipment data can reveal production levels, customers and strategic routes. Access must be limited to legitimate purposes, with retention and sharing rules.

Cybersecurity: Connected terminals and vehicles create attack surfaces. Essential controls include identity management, network segmentation, patching, incident response and operational fallback.

Competition: A dominant platform may exclude smaller carriers, impose unfair terms or use market data to compete against participants. Interoperability and competition oversight may be necessary.

Algorithmic fairness: Dynamic pricing or capacity allocation can disadvantage remote regions, small firms or low-volume shippers. Performance should be audited across user groups.

Labour and just transition: Automation can eliminate tasks while creating technical roles. Responsible strategy includes consultation, reskilling, safe job redesign and attention to affected communities.

Accountability: Contracts and regulation must clarify responsibility when an automated recommendation, sensor or platform record is wrong. “The algorithm decided” is not an adequate governance principle.

Environmental integrity: Green claims require transparent boundaries, credible emission factors and avoidance of double counting. Offsetting should not substitute for direct operational reduction where reduction is feasible.

Best-Practice Principles

  • Design around customer outcomes rather than mode loyalty.
  • Use common data definitions and interoperable event standards.
  • Combine efficiency with redundancy and recovery capability.
  • Treat terminals as strategic coordination points, not merely handling locations.
  • Evaluate full life-cycle and well-to-wheel impacts when relevant.
  • Pilot new technology in bounded, measurable environments.
  • Make contracts flexible enough to support legitimate mode changes.
  • Include small carriers, workers, communities and regulators in governance.
  • Maintain human accountability for safety-critical and legally significant decisions.
  • Review strategy continuously as technology, policy and climate conditions change.

Chapter Summary

Multimodal strategy is the integrated design of transport networks, commercial arrangements, digital systems and sustainability policies. Effective strategy evaluates total logistics performance, including cost, handling, inventory, delay, emissions, reliability and resilience. Synchromodality adds dynamic mode and route selection, but depends on substitutable capacity, interoperable data, standardised loading units and suitable contracts.

The Physical Internet proposes modular, shared and digitally routed logistics networks. Green corridors coordinate infrastructure, energy, regulation and cargo demand to accelerate decarbonisation. Digital platforms can improve matching, visibility and coordination, while AI supports forecasting and exception management subject to data, cybersecurity and accountability requirements. Autonomous systems offer operational benefits but require staged deployment, safety cases and workforce governance.

Because future conditions are uncertain, scenario planning and robust strategy are preferable to reliance on a single forecast. The strongest implementations combine measurable pilots, transparent governance, resilient network design and continuous learning.

Key Terms

Multimodality: Use of two or more transport modes in one logistics movement.

Intermodality: Movement in the same loading unit across modes without handling the goods themselves.

Combined transport: Intermodal transport with a relatively short road leg and a non-road main leg.

Synchromodality: Dynamic selection of mode and route according to real-time conditions and agreed service outcomes.

Physical Internet: Vision of an open, interconnected logistics system using modular units and shared networks.

Green corridor: Coordinated freight route designed to accelerate low- or zero-emission transport.

Platform business model: Digital model that facilitates interactions among multiple participant groups.

Network effect: Increase in platform value as participation by users grows.

Interoperability: Ability of systems, organisations or equipment to exchange and use information effectively.

Resilience: Capacity to absorb disruption, continue essential service and recover.

Reliability: Consistency of achieving the promised transport outcome.

Emission factor: Emissions associated with one unit of transport activity.

Carbon intensity: Emissions per unit of freight output, such as tonne-kilometre.

Autonomous transport: Transport operation performed with varying degrees of machine control and reduced human intervention.

Digital twin: Digital representation of a physical asset, process or network used for monitoring and analysis.

Scenario planning: Exploration of plausible future conditions to test strategy robustness.

Service-level agreement: Contractual definition of expected service performance and remedies.

Synchromodal capacity: Available alternative capacity that permits dynamic switching among modes.

Review Questions

Short Answer Questions

  1. Distinguish multimodality, intermodality and synchromodality.
  2. Why should terminal handling and delay costs be included in multimodal evaluation?
  3. State three conditions required for effective synchromodality.
  4. What is the central idea of the Physical Internet?
  5. Why is scenario planning useful for future transport strategy?

Long Answer Questions

  1. Explain how network, commercial, technological and sustainability decisions interact in multimodal strategy.
  2. Critically evaluate the benefits and limitations of green corridors.
  3. Discuss the opportunities and governance risks created by digital freight platforms.
  4. Explain how autonomous transport may affect logistics performance, employment and accountability.
  5. Develop a strategic framework for implementing synchromodality in a regional freight network.

Analytical / Application Questions

  1. A shipper can choose road-only transport or a rail–road combination. Explain which cost, service, emissions and resilience data should be collected before selecting an option.
  2. Design a five-year pilot for a green corridor connecting a port and inland logistics region. Specify participants, infrastructure, governance arrangements, metrics and risks.
  3. A platform predicts an arrival time incorrectly during a major storm and causes a missed customer delivery. Analyse the operational, contractual, data-governance and accountability issues involved.

Multiple Choice Questions with Answers

Question 1

Which feature most clearly distinguishes synchromodality from conventional intermodality?

A. Use of more than one transport mode

B. Movement in a standard loading unit

C. Dynamic switching of mode or route using real-time information

D. Use of a road vehicle for collection

Correct Answer: C. Dynamic switching of mode or route using real-time information

Question 2

In the expression E = D × M × EF, what does EF represent?

A. Freight value

B. Emission factor per tonne-kilometre

C. Expected delivery frequency

D. Equipment failure rate

Correct Answer: B. Emission factor per tonne-kilometre

Question 3

Which condition is essential for credible synchromodal operations?

A. All shipments must use rail

B. Alternative modal capacity must actually be available

C. Customers must receive no delivery promise

D. Every carrier must use the same ownership structure

Correct Answer: B. Alternative modal capacity must actually be available

Question 4

The Physical Internet primarily proposes logistics based on:

A. Closed, company-specific routes

B. Modular units, shared networks and digital routing

C. Air freight for all international cargo

D. Elimination of all logistics hubs

Correct Answer: B. Modular units, shared networks and digital routing

Question 5

Which issue is a governance risk for digital freight platforms?

A. Improved shipment visibility

B. Faster document exchange

C. Potential exclusion or unfair treatment of smaller carriers

D. More accurate event recording

Correct Answer: C. Potential exclusion or unfair treatment of smaller carriers

Question 6

Why should a multimodal strategy be tested under disruption scenarios?

A. Normal operations always overstate emissions

B. The lowest expected cost may conceal unacceptable vulnerability

C. Disruption scenarios eliminate the need for contracts

D. They guarantee that every mode will be profitable

Correct Answer: B. The lowest expected cost may conceal unacceptable vulnerability

Question 7

A green corridor generally requires coordination among:

A. Only vehicle manufacturers

B. Only customs authorities

C. Infrastructure, energy, regulation and freight-demand stakeholders

D. Only final customers

Correct Answer: C. Infrastructure, energy, regulation and freight-demand stakeholders

Question 8

Which is an appropriate early deployment environment for autonomous freight equipment?

A. An uncontrolled mixed-traffic network with no supervision

B. A fenced and controlled terminal yard

C. A route without communications coverage

D. A hazardous operation without a fallback procedure

Correct Answer: B. A fenced and controlled terminal yard

Question 9

If D is measured in kilometres, M in tonnes and EF in kg CO₂e per tonne-kilometre, the result of D × M × EF is measured in:

A. Kilograms of CO₂-equivalent

B. Tonnes per kilometre

C. Kilometres per kilogram

D. Currency per shipment

Correct Answer: A. Kilograms of CO₂-equivalent

Question 10

What is the main purpose of scenario planning in future transport strategy?

A. To predict one certain future

B. To remove all strategic uncertainty

C. To test whether a strategy remains robust across plausible futures

D. To replace operational performance measurement

Correct Answer: C. To test whether a strategy remains robust across plausible futures

Multimodal Transportation Systems
Chapter 15 of 15