Ministry of Transport and Public Works

Evaluation of the Delft Bicycle Network Plan

Homepage Manual Contents Navigation

EFFECTS OF THE DELFT DICYCLE NETWORK PLAN - Introduction

• Approach

  In the sequel, the results about effects found in the various study parts will be integrated: scattered results about the same issue will be brought together; quantitative figures will be standardized; and results not reported elsewhere will be added if necessary. Starting point is the objective of the Delft bicycle network plan, being the encouragement of the bicycle use thereby reducing car use in Delft; in addition the plan has to improve the cyclist's comfort, convenience and safety.

  By comparing changes in bicycle use in the study area with those in the control area the existence of other factors not related to the bicycle network plan can be determined. In addition to this interarea comparison the contribution of these factors to the overall changes in bicycle use is established, using national data on travel elasticities to changes in various factors like public transport fares, etc..
  From this the increase in bicycle use that would have occurred if no bicycle network plan were implemented, can be assessed.

  If the modal shifts in the study area are larger than may be expected from these other factors, it may be assumed that the bicycle network plan has a positive effect. This net increase is the true and unconfounded effect of the bicycle improvements made in the study area.

• Definitions

  The effect will be mainly measured by means of the total distance travelled by bike or car, sometimes called total kilometers travelled. This total distance equals the product of the number of trips and the average trip length. A change in the total distance travelled may be caused by a change in both these factors.

  Effects are expressed as percentages changes in the level of bicycle or car use, measured by total distance travelled, volumes, number of trips, etc. between 1982 and 1965.

  Changes in bicycle or car use between 1932 and 1985 can be measured correctly only if demographic changes are accounted for. Therefore bicycle or car use per capita is used a variable in most cases, e.g. trips per day , total distance travelled per day per capita.

  The components of the bicycle network plan, the effects of which are to be determined, are located in the study area (Delft North-West). Both residents of this area and other travellers may benefit from these improvements. When determining the plan's affect both bicycle use by residents of the study area and total distance travelled by bicycle in this area are relevant indicators. The latter distance stems from internal, external and through trips of the study area, made by residents and non-residents as well.