Scottish Government

Reduce Traffic Congestion

DESCRIPTION:

This indicator measures the percentage of journeys made by the driver of a car or a van that were delayed due to traffic congestion. This is gathered through the Travel Diary component of the Scottish Household Survey.

This indicator monitors drivers' own perception of whether or not their journeys by car were delayed due to congestion, regardless of the journey type or the nature of the roads they travelled on. It is not an actual figure for time lost due to congestion (e.g. as in Transport Scotland's Congestion on Scottish Trunk Roads publication). SHS data is used as it is representative of the whole of Scotland whereas congestion on trunk roads indicators are modelled using data from roadside counters at a limited number of points on the trunk road network.

The SHS indicator is a proxy for efficient, reliable transport networks as no single measure is available to capture overall performance.

SOURCE:

The data for this indicator are gathered through the Travel Diary element of the Scottish Household Survey (SHS). The published results are available below.

http://www.transportscotland.gov.uk/analysis/statistics/publications/shs-travel-diary-results-previous-editions

The SHS is a continuous cross-sectional survey: interviewing takes place all year round. Each year, about 15,500 households across Scotland are interviewed. Since 2012, a random adult in each household is asked to complete the Travel Diary.  (From 2007-2011 the travel diary was only asked of a random adult in 75% of households).

The SHS Travel Diary collects information about travel for private purposes or for work or education, provided the main reason for the journey is not in the process of business. It includes the following types of travel - personal travel for domestic, social or recreational purposes and journeys made to take or escort someone else.

The figures are produced from survey information about journeys (or stages of journeys) that were reported as having been made as the driver of a car or a van. In each case, the interviewer asks "was this part of your trip delayed due to traffic congestion?" No definition of traffic congestion is given, so respondents can interpret the term as they wish.

DEFINITIONS:

Traffic Congestion No definition of traffic congestion is given to survey respondents, so respondents can interpret the term as they wish.

A journey, is defined as a one-way course of travel having a single main purpose. Outward and return halves of return journeys are treated as two separate journeys

A journey can consist of one or more stages a new stage is defined when there is a change in the form of transport or when there is a change of vehicle requiring a separate ticket. This indicator includes stages of journeys in the percentage.

BASELINE AND PAST TRENDS:

The baseline year is 2006. Baseline value is 12.7%.

CRITERIA FOR RECENT CHANGE ARROW:

Any difference within +/- 1 percentage points of last year's figure suggests that the position is more likely to be maintaining than showing any change. A reduction of 1 percentage points or more suggests the position is improving; whereas an increase of 1 percentage points or more suggests the position is worsening.

For information on general methodological approach, please click here.

FUTURE ISSUES OR REVIEWS:

No issues.

ASSOCIATED TARGET:

No associated target.