Option Generation and Preliminary Appraisal
This chapter summarises initial list of options generated, the initial sift of these options, and the preliminary appraisal of the options identified. The early qualitative appraisal of high-level options was undertaken, providing an initial indication of performance against criteria, and identifying design considerations and areas where mitigation may be required to inform further option development and packaging.
Option Long List
Options have been generated based on the suite of examples examined within the literature review. These examples were further discussed and consolidated into a list of options which constitute all reasonable theoretical instruments which could be applied to address the central research question.
The overarching options are:
- Cordon-based charging: Any charge imposed for entering a pre-defined area by passing over a cordon, typically a ring around a particular area, route, or corridor. This could include any charge for using specific roads, such as the trunk-road network or structures, such as bridges. As such, cordon-based schemes could be imposed on longer distances, via cordons placed at access points to the trunk road network or specific pieces of road infrastructure, or to specific areas, via cordons at access points to those areas.
- Area-based charging: Any charge imposed for moving within a pre-defined area, captured by ANPR, and charged per day. Most congestion charge models would be considered under this option. Area based charging is suited to local schemes in and around a specific urban centre. LEZs are an example of a type of area charge which is already in use in Scotland.
- Parking Charges: This option includes consideration of any change to the cost of parking via either public parking charges, workplace or out-of-town parking levies, or residents permits.
- Vehicle Levy: A charge which applies to the ownership of a vehicle enabling targeting of different vehicle types or sizes.
- Fuel Levy: Charges which apply to the consumption of fuel or energy enabling targeting of consumption which is linked to vehicle use.
- Levies on Consumables: Adding a charge to environmentally damaging car consumables, such as tyres and brake pads could reduce demand and promote more conservative driving behaviour. Such a measure could also incentivise companies to make improvements to tyre and brake pad durability.
- Distance based charging: A charge which can be imposed according to any length of journey on any part of the road network. A more innovative or theoretical model of national road user charging which enable specific journeys to be charged at individual rates would fall under this option.
- Time-based charging: This option considers any charge based on the time spent travelling, rather than the length or location of the journey.
- Vignettes: Permits to use a particular road or road network for a given period, ranging from a week to a year.
- Road-space reallocation: Road-space reallocation encompasses any option which specifically seeks to manage car demand by removing road capacity.
- Road-space rationing: Any option which limits the number of vehicles allowed to use the road during certain times, either by an arbitrary allocation or on dedicated ‘car free days’.
- Development planning: This option would be implemented though review of local development planning standards to reduce or eliminate parking provision from urban centres.
Consolidation and Sifting
Options considered within the literature review which do not appear in the list of options generated above, have been judged to be complementary measures rather than stand-alone TDM interventions. These interventions will be considered during Option Development, which will include packaging of options in order to mitigate negative impacts identified within the appraisal. These include:
- Vehicle occupancy charging and priority.
- Behaviour change programmes.
Five of the options generated have been sifted out prior to the appraisal as they are judged to be an inappropriate way of achieving the intended objective and addressing the identified transport problems directly. These are:
- Levies on consumables: This option could be of significant benefit to reducing the overall environmental impact of consumables such as tyres and brake pads while providing a consistent revenue stream. However, as these consumables are an infrequent purchase, the cost of the levy would need to be set at such a level as to be unacceptable to the public in order to contribute significantly to the reduction in car kilometres. In addition, the measure could potentially lead to people driving with tyres and brake pads in worn and unsafe condition.
- Time-based charging: This option has been sifted out due to the likelihood that it would incentivise unsafe road user behaviour, principally, the risk of speeding.
- Vignettes: The use of vignettes is being phased out across many countries which had previously used them in favour of distance-based charging, as vignettes do not reflect actual road use and are highly regressive in the way the charge is distributed.
- Road-space reallocation: Road-space reallocation takes place as a consequence of the ongoing process of re-balancing transport infrastructure away from private vehicles and towards more sustainable and inclusive modes, via introduction of bus lanes, wider pavements, trams and cycleways in line with the sustainable investment hierarchy. However, road-space reallocation is rarely implemented in isolation as a specific means of transport demand management and should be considered as complementary to any TDM measure. It is considered that the suite of public and active travel projects recommended within STPR2 would encompass some element of road-space reallocation and help provide this mitigation.
- Road-space rationing: Road-space rationing has been introduced in certain locations, such as Mexico City, as an emergency measure, in response to dangerous levels of air pollution. As such it is not considered to be a long term and sustainable way of managing demand.
- Development planning: Development planning must encompass a range of considerations specific to the needs of the local area, housing type, and community need. It is likely that local authorities will review their housing requirements and parking standards in line with the guidance set out in NPF4. However, demand reduction as a result of changes in development planning, such as reduction in parking provision, would be a long term effect and is unlikely to directly address the objective of reducing car use in the timeframe required.
Preliminary Appraisal
Each option was assessed qualitatively against the following appraisal criteria:
- Research Objective
- Reduce Car Kilometres by 20% by 2030
- Deliverability
- Feasibility
- Affordability
- Public Acceptability
- STAG Criteria
- Environment
- Climate Change
- Health, Safety and Wellbeing
- Economy
- Equality and Accessibility
- Policy Alignment
The appraisal will also consider the option’s performance in the Sustainable Investment Hierarchy
Assessment against the research objective, STAG criteria and policy alignment was assessed against a seven point scale. For the deliverability criteria, a risk-based assessment approach was used. The assessment scales were defined as follows:
|
Seven-point Scale |
|
|
Major Positive |
+++ |
|
Moderate Positive |
++ |
|
Minor Positive |
+ |
|
Neutral |
0 |
|
Minor Negative |
- |
|
Moderate Negative |
-- |
|
Major Negative |
--- |
|
Deliverability Risk Scale |
|
High |
|
Medium |
|
Low |
Table 3‑1 overleaf sets out the summary of the assessment, and Table 3‑2 shows the decision and rationale for each option, alongside design considerations and proposed mitigation and packaging where applicable.
|
Research Objective |
Implementability (Risk) |
STAG Criteria |
Policy Alignment |
Position in Sustainable Investment Hierarchy |
|||||||
|
Reduce Car km by 20% by 2030 |
Feasibility |
Affordability |
Public Acceptability |
Environment |
Climate Change |
Health, Safety & Wellbeing |
Economy |
Equality & Accessibility |
|||
|
Cordon Charging |
+ |
Medium |
Medium |
High |
++ |
+ |
+ |
+ |
- |
++ |
Makes better use of existing capacity |
|
Area Charging |
+ |
Medium |
Medium |
High |
+++ |
+ |
+ |
+ |
- |
++ |
Makes better use of existing capacity |
|
Parking Charges |
0 |
Low |
Medium |
Medium |
+ |
+ |
0 |
- |
- |
++ |
Makes better use of existing capacity |
|
Vehicle Levies |
+ |
High |
Low |
Medium |
+ |
+ |
+ |
+ |
-- |
++ |
Makes better use of existing capacity |
|
Fuel Levies |
++ |
High |
High |
Medium |
+ |
+ |
0 |
+ |
- |
++ |
Makes better use of existing capacity |
|
Distance Charging |
+++ |
Medium |
Medium |
Medium |
+ |
++ |
+ |
+ |
0 |
++ |
Makes better use of existing capacity |
|
Decision |
Rationale |
Design Considerations |
Mitigation and Packaging |
|
|
Cordon Charging |
Retain |
· Targets most congested areas; maximising efficiency, reducing accident risk and improving air quality · Targets short distance trips which are easier to shift and more likely to shift to active modes with health benefits |
· Best suited to urban areas · Equality and accessibility risks due to affordability · Public acceptability risks amongst residents · Feasibility / affordability risks with ANPR procurement / installation |
· Targets high concentration, short distance urban trips but could be combined with other options to increase effectiveness · Discounts or exemptions to mitigate affordability / acceptability risks |
|
Area Charging |
Retain |
· Targets most congested areas; maximising efficiency, reducing accident risk and improving air quality · Targets short distance trips which are easier to shift and more likely to shift to active modes with health benefits |
· Best suited to urban areas · Equality and accessibility risks due to affordability · Public acceptability risks amongst residents · Feasibility / affordability risks with ANPR procurement / installation |
· Targets high concentration, short distance urban trips but could be combined with other options to increase effectiveness · Discounts or exemptions to mitigate affordability / acceptability risks |
|
Parking Charges |
Retain as a complementary measure |
· Mitigates boundary effects of area or cordon charging |
· Most effective where there isn’t cheap alternative parking · Effectiveness dependent on charge type / enforcement · Equality and accessibility risks due to affordability · Public acceptability risks amongst residents / businesses · Affordability risks due to enforcement costs |
· Effective in urban areas and key destinations but could be combined with other options to increase effectiveness · Discounts or exemptions to mitigate affordability / acceptability risks |
|
Vehicle Levies |
Do not retain |
· Disincentivises vehicle ownership but unlikely to be feasible in required timeframe due to political and constitutional issues |
· Most effective in locations with good alternatives to car · No disincentive to travelling long distances once yearly charge has been paid · Equality and accessibility risks due to affordability · Public acceptability risks would be lower for a hypothecated charge reinvested in transport improvements than for a tax · Feasibility risks for both a tax, which would require further devolution, and a charge, which would require new primary legislation. |
· N/A |
|
Fuel Levies |
Do not retain |
· Disincentivises fuel consumption which is linked to distance travelled but unlikely to be feasible in required timeframe due to political and constitutional issues and feasibility risks in adapting to EV charging |
· Disincentivises fuel consumption which is directly linked to carbon emissions · Equality and accessibility risks due to affordability, particularly rural areas with fewer alternatives and typically longer travel distances · Feasibility and affordability risks, with uncertainty around how electricity used for vehicle fuel could be differentiated and the potential implementation costs |
· N/A |
|
Distance Charging |
Retain |
· Disincentivises distance travelled, linking directly to research objective · Could be implemented on a local or national level and monitored / tailored to meet the needs of urban and rural communities equitably and to target specific journey. |
· Requirement to measure / estimate milage which could be done using in-car telematics or regular milage submissions via an online portal. · Feasibility risks with universal adoption of on-board devices and installation of a backup and checking system |
· Targets longer journeys but could be done in combination with other options to increase effectiveness · Discounts or exemptions to mitigate affordability / acceptability risks |