Many of the terms in this glossary can be defined in several ways. The definitions provided are the ones which have been used in the PROSPECTS project. Definitions of individual policy instruments are not included but can be found in KonSULT.

The meanings of words in italics can be found elsewhere in this glossary.

Accessibility The accessibility of an activity to an individual is the ease with which the individual can get to the places where that activity can be performed

Appraisal Assessing the relative merits of strategies before they are implemented

Barrier An obstacle which prevents a given policy instrument or strategy being implemented, or limits its implementation in some way. A constraint is similar

Complementarity A condition where the component instruments of a strategy have a greater beneficial effect than any instrument on its own

Cost-benefit analysis Appraisal of the economic efficiency of a strategy, by weighing the costs of a strategy against the benefits it might bring, over a number of years into the future

Efficiency (or economic efficiency) Maximising the benefits which users can gain from the transport system, after taking account of the costs of provision and operation of the system

Environment Environmental impacts include noise, air pollution, vibration, visual intrusion, severance, intimidation, and the loss of flora, fauna and historic buildings

Equity Equality, especially between different groups in society, in opportunities to travel, costs of travel and environmental and safety impacts of travel

Evaluation The process of finding out, after implementation, what the real impacts of a strategy have been and how they compare to what was expected beforehand

Indicator Ways of quantifying objectives: for example, road accident numbers are one indicator of safety

Instrument Also known as measures, instruments are the specific components (e.g. lower bus fares, road pricing) of a strategy

Intergenerational equity Meeting the needs of the present without compromising the ability of future generations to meet their own needs. (See also the full definition of sustainability in Section 7 of this Guidebook)

Integration Integration involves combining instruments so that they reinforce one another and create synergy in meeting objectives

Land use The function of a given area of land. Examples of types of land use include: residential, industrial, commercial, agricultural and recreational

Liveable streets Pleasant street and outdoor conditions. It includes the positive external effects on social, cultural and recreational activity in neighbourhoods

Management How the transport system is managed and operated, usually to reduce congestion and accidents and to protect the environment. Demand management encompasses measures to affect how people travel. Traffic management is the allocation of road space to different users

Mobility Ease of moving about. Often specifically meaning access to a private vehicle for travel

Model A (mathematical) representation of the relationships within the land use / transport system; widely used to predict the outcomes of transport strategies

Monitoring A continuous programme of measuring changes in the transport system

Multi-criteria appraisal Appraisal against more than one objective

Objective A broad statement of the improvements which a city is seeking. Objectives specify the directions for improvement, but not the means of achieving it

Objective function One or more objectives incorporated into a mathematical expression, often used in modelling as part of an optimisation process

Optimal An optimal strategy is one which performs best against its objectives

Optimisation A (mathematical) process to determine the optimal transport strategy

Policy A broad approach towards transport and land use planning, including the specification of objectives and the choice of a strategy and its component instruments

Pricing The way in which users are charged for using the transport system. Road pricing is a pricing system where motorists pay directly for using the roads

Reliability For the road system, reliability means little daily variation in travel time. For the public transport system, it means that vehicles depart on time and arrive at stops on schedule

Revenue Income from transport pricing

Robust Likely to be successful in a wide range of future scenarios

Scenario A possible future set of demographic and economic conditions

Sensitivity analysis Is a programme of tests of a strategy to find out how its performance changes with changes in the assumptions made

Stakeholder All people and organisations which have an interest in the transport system

Strategy A combination of instruments to meet a given set of objectives

Synergy A condition where the component instruments of a strategy have a greater beneficial effect than the sum of their parts

Target An aimed-for value of an indicator

Threshold The value of an indicator which should not be exceeded

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Text edited at the Institute for Transport Studies, University of Leeds, Leeds LS2 9JT