3 What to Monitor
In June 1999 the Ministry for the Environment, through the EPI Programme, released Environmental Performance Indicators: Proposal for indicators of the environmental effects of transport, a discussion document. The purpose of Proposal for indicators of the environmental effects of transport was to encourage consideration, discussion and ultimately agreement on a core set of indicators for the environmental effects of transport.
To assist with the selection and prioritisation process, MfE obtained assistance from the Transport Indicators Focus Group (TIFG). TIFG was a group comprising experts from regional councils, central government agencies, academia and private sector consultants. A set of 13 proposed transport indicators was developed that included the four indicators discussed in this guide:
- Vehicle fleet composition (by vehicle type, engine size, fuel type, and age)
- Travel activity (vehicle kilometres travelled by road vehicles annually)
- Travel time (change in level of road congestion over time) and
- Mode of journey to work.
The environmental pressures that result from any transport activity are related to the characteristics of the vehicle fleet that is undertaking this activity. The types of vehicle in the fleet and their engine sizes determine the amount of fuel used. While the age of the vehicles and the type of fuel used, determine the environmental consequences of this travel (Indicator 1).
Exactly how much pressure travel in these vehicles places on the environment is directly related to the volume of travel activity, which may be measured in terms of total vehicle kilometres travelled (Indicator 2).
Transport or travel seldom results in direct benefits to users, but is more generally undertaken to fulfil a specific purpose or to realise a specific opportunity. One key purpose of travel is to engage in employment. The journey to work (Indicator 3) is an important transport activity because these journeys:
- are undertaken by a significant proportion of the population on a regular basis
- occur typically within a narrow time interval due to the generally regular nature of employment and
- result in periods of congestion that generate substantial economic and environmental effects.
Because the journey to work is related to a single purpose, is regularly undertaken and often involves common paths or destinations, it is more likely to be effectively targeted by environmentally focused transport policies. Monitoring how people choose to travel to work and by implication home from work is one way of reporting on changing transport trends and the pressure that this activity places on the environment. That pressure will be related to:
- the number of people travelling
- the distance of travel
- their mode of travel
- the characteristics of the mode of travel
- the conditions (congestion) under which they travelled.
Traffic congestion in its own right is a measure of the demand for road transport and the pressure this places on our environment. In the absence of increases in capacity, increasing traffic volumes result in more and more congestion, experienced for increasingly longer periods of the day. The level of congestion serves as an indicator of the pressure road transport is placing on our environment. Travelling in congested conditions places additional pressures on the environment as drivers find it more difficult to maintain a steady speed. Fuel consumption is increased as are certain emissions while increased braking deposits more detritus from tyres, brakes and transmissions. Travel time (Indicator 4) provides a measure of congestion effects.
The monitoring programmes for air and water quality report on the state of elements in our environment. These programmes are essentially concerned with obtaining multiple measures to determine the quality of specific environments. The monitoring guidelines for such programmes follow a typical format, which outlines the methods to be used, site selection, equipment, recording and data reporting and management. This task-based format is suitable for standardising a range of essentially similar measures, the data for which is collected by a number of agencies.
The Environmental Indicators for Transport, on the other hand, seek to measure quite different pressures or features which are only loosely associated. In addition, much of the data is currently collected centrally (by LTSA, Transfund, Transit NZ and other agencies) using existing systems. Given the wide variation in the current approach, a task-based format is not a suitable framework for explaining the monitoring process for transport indicators.
This protocol explains each of the indicators in turn including how these indicators should be monitored and the existing data sources available for the indicator. This will allow the user to quickly determine where the information should be obtained, how it has been collected and how it should be analysed and reported. Where relevant, monitoring methodologies for information that is not readily available are provided, and guidance is given on how to use this information with the existing data sets.
