Why use land use planning to encourage less personal motorised travel?

The importance of the interactions between spatial (land use) planning and management, and the design, operation and use of transport systems, is fully recognised. Important aspects of this are (Cost 332):

• the spatial organisation engendered by the evolution of the production process increases personal mobility requirements (and those for goods movements),
  
• low density development, particularly in the suburbs, has encouraged the growth of travel and of multi-car households;
  
• the growing polarisation of commercial structures has also led to an increase in personal travel, particularly by car.

The reversal or reduction of these land use development trends will tend to reduce the need to travel in general and travel by car in particular. Land use changes, however, take quite a long time, so this is not a short-term policy instrument.

The trends listed above may be illustrated by the cases shown in the following table:

Source: Lucas, Marsh and Jones, p.16.

The table below indicates how various land use design features are estimated to reduce per capita vehicle trip generation compared with conventional development that lacks these features (Online TDM Encyclopaedia).

Travel Impacts of Land Use Design Features (Dagang, 1995)

Source: Online TDM Encyclopaedia

Demand impacts

Increasing development densities and altering the development mix have an effect on demand in two ways:

• Reducing the need for motorised travel (especially private motorised travel) by ensuring origins and destinations are closer together (the topic of this section);
  
• Encouraging public transport use by improving conditions to enable public transport to operate more efficiently (dealt with separately under 'Encouraging Public Transport Use Through Land Use Planning' ;

It is the demand impact of the first of these which is the subject of the following table and the remainder of this section.

	= Weakest possible response,		= strongest possible positive response
	= Weakest possible negative response,		= strongest possible negative response

= No response

Short and long term demand responses

Of all the instruments contained in these pages, land use instruments are perhaps the ones which, potentially at least, can have the greatest impact on reducing the amount of motorised travel. However, they are also the ones which take the longest to implement and thus to bear fruit. The greatest opportunities for change are in the circumstances of entirely new development, when land use densities and mixes may be specified in advance. Even in these conditions however, results will take years to materialise

Response	-	1st year	2-4 years	5 years	10+ years
Change departure time	-
Change route	-
Change destination	Change job location
-	Shop elsewhere
Reduce number of journeys	Compress working week
-	Trip chain
-	Work from home
-	Shop from home
Change mode	Ride share
-	Public transport
-	Walk/cycle
Sell car	-
Change home location	-

	= Weakest possible response,		= strongest possible positive response
	= Weakest possible negative response,		= strongest possible negative response

= No response

Level of response

The amount of reduction in the amount of motorised travel in response to land use instruments, will depend on:

• the scale of the land use changes;
  
• the design and type of the changes, in terms of density and mix;
  
• the speed with which the changes are effected.
  

In all cases, there will be no response in the short term and very little in the medium term, as indicated in the table above.

One study of travel patterns in a North American suburb found the elasticity of transit (public transport) mode split with respect to land use density to be +0.10 to +0.51, depending on type of land use. This means that each 1.0% increase in density increases public transport use by 0.1-0.51% (Cervero (2002) in Online TDM Encyclopaedia).

Ewing and Cervero (2002) calculate the elasticity of per capita vehicle trips and vehicle travel with respect to various land use factors, as summarized in the table below. For example, this indicates that doubling neighbourhood density reduces per capita car travel by 5%. Similarly, doubling land use mix or improving land use design to support alternative modes also reduces per capita car travel by 5%. Although these factors may be small, they are cumulative. (Online TDM Encyclopaedia)

Typical Elasticities of Travel With Respect to the Built Environment (Ewing and Cervero, 2002) in Online TDM Encyclopaedia))

This table shows the elasticity values of Vehicle Trips and Vehicle Miles Travelled (VMT) with respect to various land use factors.

This suggests that neighbourhood design factors (density, mix and design) can reduce per capita vehicle travel on the order of 10-20%, while regional accessibility factors (i.e., where a neighbourhood is located with respect to the urban centre) can reduce car travel by 20-40%. (Online TDM Encyclopaedia)

Supply impacts

The supply implications are as follows:

• There will not be an increase in the supply of road space from land use instruments per se, though there might be additional local requirements, e.g. for access to new development, including by bus;
  
• If the land use policies are implemented on a regional scale, there could be a nett reduction in the need for road space (compared with doing nothing) in line with the decrease in the amount of travel;
  
• Higher density development could improve conditions for public transport and thus encourage greater public transport supply; (dealt with separately under 'Encouraging Public Transport Use Through Land Use Planning';
  
• Reduction in private motorised travel could encourage an increase in the supply of cycle and pedestrian facilities;
  
• Any reduction in car ownership would reduce the need for residential parking supply;
  
• Any reduction in 'motorised destinations' would reduce the need for non-residential parking supply.

Financing requirements

Though the costs of new development are considerable and land use solutions are, at their most extreme, the most expensive of the policy instruments contained in these pages, the cost usually falls in the main on the private sector (through investors, developers and occupiers). However, local authorities may have to bear some additional indirect costs (provision of extra traffic control, parking, public transport interchanges, etc).

Though it is difficult to cost this instrument, the range of possibilities being so large, some comments on cost can nevertheless be made.

Firstly, regarding individual developments, it has been estimated (Lucas, Marsh and Jones, p.19) that if development conforms to a standard to reflect sustainable development, construction costs will rise typically between 5 per cent and 20 per cent. Unfortunately the proportion of this extra cost related solely to attaining sustainable transport is not known but clearly there would be some additional cost if land use development had to conform to sustainable transport criteria.

There are ways of financing the extra costs of achieving a transport-friendly development policy, particularly where the extra cost would normally fall on the local authority. These ways include:

• Commuted payments
  
• Developer contributions

If development costs are looked at region-wide, an alternative picture on costs may occur, as illustrated in the following table (costs in Canadian dollars) (Online TDM Encyclopaedia)

Estimated 25 Year Public Costs for Three Development Options
(Blais, 1995)

This table shows substantial public savings for higher density land use patterns associated with transport-friendly development.

Finally, one interesting issue regarding financing is the possibility of higher land and property values arising from improved accessibility, and how the local authority can get its hands on a slice of it.

Expected impacts on key policy objectives

Increasing land uses densities and modifying development mix encourage people to change their travel behaviour and in particular to travel less by car, through the mechanisms explained earlier. The resulting reduction in car travel can have significant effects on the various Konsult objectives as shown in the table below. Once again, these impacts are approximate as the scale of the effects depends largely on the scale of land use changes.

	= Weakest possible positive contribution,		= strongest possible positive contribution
	= Weakest possible negative contribution		= strongest possible negative contribution

= No contribution

Expected impact on problem alleviation

The expected impacts of changes in land use density and mix on problem alleviation are summarised in the following table.

	= Weakest possible positive contribution,		= strongest possible positive contribution
	= Weakest possible negative contribution		= strongest possible negative contribution

= No contribution

Expected winners and losers

It is difficult to see how there can be any losers if policies of land use density and mix are wisely applied. This is because there should be a wider range of destinations within a given distance and public transport operations are made easier. There is no discouragement per se to any motorised mode: the reduction in traffic by reducing the need to travel will in fact benefit all motorised modes.

Group	Winners / losers	Comment
Large scale freight and commercial traffic		Reduced congestion
Small businesses		Reduced congestion, better public transport access for employees and customers
High income car-users		Reduced congestion
People with a low income		Public transport access will improve
People with poor access to public transport		Public transport access will improve
All existing public transport users		Public transport access will improve
People living adjacent to the area targeted		They may benefit from reduced congestion and improved or increased public transport supply.
People making high value, important journeys		Bus and car access improved
The average car user		Where they are able to travel more efficiently, saving time and money. Plus getting more exercise through modal shift to walking and cycling, and experiencing the community benefits, which accrue from these modes.

	= weakest possible benefit,		= strongest benefit
	= weakest possible disbenefet,		= strongest possible disbenefit

= neither wins nor loses

Barriers to implementation

There are potentially severe barriers to implementation, particularly financial and related to feasibility. Legal barriers may also be serious in cases where the current planning legislation would need amendment for this instrument to be implemented.

Barriers to implementation
Barrier	Scale	Comment
Legal		If legislation not in place
Financial		Unless developers can be persuaded to pay in some way for ‘sustainability upgrade’ of their developments
Political		Time needed to effect changes may make the instrument politically unattractive
Feasibility		Not infeasible per se but amount of time needed may reduce feasibility

= minimal barrier,

= most significant barrier