Highways Agency

Assessment Strategy for the M1 HOV Pilot

The DfT have decided after careful consideration that an HOV lane is not appropriate on the 6a to 10 section of the M1 and all work to implement HOV on this motorway widening scheme has been stopped. With this announcement from the Secretary of State came the publication of a feasibility study into advanced motorway signalling and traffic management -which can be found on Department for Transport website via the following link:

http://www.dft.gov.uk/pgr/roads/network/policy/mtorsigntrafmanagement/

The study report contains more information on the M1 HOV lane (paragraphs 7.35 to 7.36, and the wider experience and opportunites from HOV lanes in paragraphs 7.24 to 7.38).

Executive Summary

High Occupancy Vehicle (HOV) lanes have been used successfully in other countries (primarily in the USA, and also in Spain and Australia). To date, HOV lanes have only been implemented in the UK on short sections of dual carriageway (in Leeds and South Gloucestershire), and the Highways Agency is looking to pilot an HOV lane on the strategic road network.

An HOV lane is to be implemented on both carriageways of the M1 between Junctions 7 and 10. The HOV lane will be implemented as part of the planned widening of this section of motorway, which is scheduled to commence in November 2005. If successful, the scheme is likely to be extended to the next section of the M1 to be widened (Junctions 10 to 13).

The Highways Agency is to appoint a Monitoring Consultant to assess the effect of introducing an HOV lane onto the M1 pilot site. A work package has been established to review the objectives of installing the HOV lane, to determine a potential assessment strategy for the HOV Pilot scheme, to produce a draft specification describing the recommended monitoring requirements, and to carry out a systematic review of existing HOV schemes. This report describes the results of the second part of this work package (the development of an assessment strategy for the scheme).

The objectives of installing an HOV lane have already been determined. The objectives were rated according to importance (in terms of benefits to the user) and the expected impact of the HOV scheme in achieving the objectives. The objectives were reviewed in accordance with the advice on the Transport Analysis Guidance Website (WebTAG).

The report details the assessment options for the scheme. Possible methods of assessing the objectives of the scheme have been listed and rated according to cost and the feasibility of measuring changes. The lists provide options for assessment; these options have been used to recommend an assessment strategy, which could be used to establish the impacts of the scheme and to optimise the operation of the scheme.

The assessment strategy has been developed in accordance with the recommendations arising from a Peer Group review of HA projects. The options for assessment and the recommended assessment strategy have been reviewed by an independent panel of experts.

The HOV lane will be implemented by widening the M1, and the HA will appoint a Scheme Consultant for the widening scheme, who will also be responsible for the implementation of the HOV scheme. This report specifies the scope of the work required from the Monitoring Consultant, and separates it from work to be carried out by the Scheme Consultant.

The assessment strategy described in this report will be used to develop a draft monitoring specification for the Monitoring Consultant for the M1 HOV Pilot scheme.

1. Introduction

A preliminary study into suitable locations for HOV lanes in the UK identified a number of potential sites including the southbound section of the M1 between Junctions 10 and 7. It has subsequently been decided that an HOV lane should be implemented on both carriageways of the M1 between Junctions 7 and 10 because of the favourable business case. The HOV lane will be implemented as part of the planned widening of this section of motorway, which is scheduled to commence in November 2005.

The objectives of installing an HOV lane have already been determined (Rees, 2005). The objectives were rated according to importance (in terms of benefits to the user) and the expected impact of the HOV scheme in achieving the objectives. The objectives were reviewed in accordance with the advice on the Transport Analysis Guidance Website (WebTAG)¹.

This report describes the results of the second part of this work package (the development of an assessment strategy for the scheme). The report details the assessment options for the scheme. Possible methods of assessing the objectives of the scheme have been listed and rated according to cost and the feasibility of measuring changes. These lists provide options for assessment; these options have been used to recommend an assessment strategy, which could be used to establish the impacts of the scheme and to optimise the operation of the scheme. This strategy will be used to determine the recommended monitoring requirements for the M1 HOV Pilot scheme.

The assessment strategy described within this document has been developed in accordance with the recommendations arising from a Peer Group review of HA projects (Powell, 2001).

Section 2 of this document describes the M1 HOV Pilot scheme. Section 3 describes the objectives of the scheme. Sections 4 and 5 describe the scope of the assessment, the assessment options and the recommended assessment strategy. Section 6 contains recommendations for an approach to publicising the scheme and the results of the assessment.

Section 7 provides conclusions and a brief description of the next phase of work to obtain the recommended monitoring requirements. Section 8 lists references to other reports.

WebTAG provides detailed guidance on the appraisal of transport projects and wider advice on scoping and carrying out transport studies. It brings together several advice documents, including the Guidance On Methodology for Multi-Modal Studies (GOMMMS). back [1]

2. The M1 HOV Pilot

The HOV scheme is to be implemented on Junctions 7 to 10 of the M1 (see Figure 1).

Figure 1 - The M1 Junctions 7 to 10

Junction 7 is a limited access junction, with no access to the M10 from the northbound M1, or from the M10 to the southbound M1. There is only a short distance (approximately 1km) between Junctions 7 and 8.

Currently, J7-10 of the M1 has three lanes on each carriageway, except for J9-10 northbound, which has four lanes.

The HOV lane will be implemented as part of a widening scheme (to four lanes in each direction), with the additional lane on each carriageway between Junctions 7 and 10 to be used as an HOV lane. This should increase public acceptance of the scheme, as it has been observed (e.g. in Holland) that reallocating an existing lane as an HOV lane is unpopular.

The exact design of the HOV scheme is still to be decided. However, it is expected that:

the HOV lane will be the offside lane of each carriageway (i.e. nearest the central reservation);
the HOV lane will operate during peak hours only;
the HOV lane will be open to buses, motorcycles and vehicles (cars or LGVs) with more than one occupant (i.e. a 2+ lane). HGVs will not be permitted to use the HOV lane.

It is still to be decided whether any speed restriction will be imposed on the widened section of the M1 (such as the 60mph limit between Junctions 3 and 2 of the M4 in the vicinity of the bus lane). It is likely that a Variable Speed Limit system (similar to the Controlled Motorways scheme on the M25) will be implemented as part of the widening scheme. If such a system is implemented, it would provide the means to impose a speed restriction (e.g. 60mph) over the whole carriageway while the HOV lane is operational during peak periods, but to have no speed restriction at other times of day (unless an incident occurs or there are high flow levels).

If the HOV scheme is successful, it is likely to be extended to cover Junctions 10-13 of the M1. The J10-13 section is due to be widened once the J7-10 widening is complete (this is estimated to be during 2008). Any lessons learnt from the J7-10 scheme (e.g. in the design of the scheme) will be incorporated in the J10-13 scheme.

3. Objectives of the M1 HOV Pilot

A workshop was held on 6th December 2004, at which the Highways Agency defined the objectives for the M1 HOV Pilot scheme. The overall scheme objective is:

"To assess the case for further rollout of HOV lanes".

More detailed objectives of the M1 HOV Pilot were also defined at the workshop. These objectives have been reviewed (Rees, 2005). The review also considered the general objectives of major traffic schemes and recommendations arising from a Peer Group review of HA projects (Powell, 2001).

All of the objectives have been classified by type:

The objectives that may have a direct impact, grouped by subject (Economy, Safety, Environment, Public, Accessibility and Integration).
The general operation of the scheme. The Pilot scheme will provide information that can be used to improve the operation of the M1 scheme, and also to optimise the design of other HOV schemes.

The subject headings for the objectives that may have a direct impact are as recommended by WebTAG. WebTAG also lists specific Environment, Accessibility and Integration objectives that should be considered as part of any road scheme. These have been considered as part of the review of objectives, although many are not directly relevant to motorway schemes (in particular, the Accessibility and Integration objectives).

The objectives for the M1 HOV scheme are:

Economy: To maximise person throughput whilst minimising journey time and journey time variability. This overall objective can be broken down as follows:
1. To reduce congestion by reducing the number of vehicles in the M1 corridor as compared to the estimated number of vehicles that would use this route when widened to four lanes. This will be achieved by encouraging higher occupancy.
2. To improve journey times of HOVs in the M1 corridor as compared to the estimated journey times if the widened fourth lane was to be used as a normal operating lane.
3. To improve journey time reliability for HOVs in the M1 corridor as compared to the estimated reliability if the widened fourth lane was to be used as a normal operating lane.
4. To minimise the delay for non-HOV vehicles in the M1 corridor as compared to the estimated delay if the widened fourth lane was to be used as a normal operating lane.
Safety: To maintain and where possible improve safety levels in the M1 corridor. This will be compared to the estimated safety levels if the widened fourth lane was to be used as a normal operating lane.
Environment: To avoid adverse landscape effects. The HOV lane and associated signing should be as unobtrusive as possible. WebTAG also requires noise and emission levels to be considered. The only changes to these as a result of the HOV lane are likely to be associated with changes to numbers of vehicles, and are likely to be very small.
Public: To improve public awareness of HOV schemes and to establish their benefits, including their ability to influence travel behaviour more generally.
Accessibility: None.
Integration: None.
Integration: None.
Operational Issues:
1. To optimise, as far as possible, the benefits from the M1 HOV scheme.
2. To help to plan any further HOV schemes.
Business Case:
1. To assess the case for any further rollout of HOV schemes.
2. To improve the HA's ability to forecast the effect of any further HOV schemes.

All of the objectives listed above have been reviewed and agreed by the Highways Agency.

The Economy and Safety objectives refer to the M1 corridor because the HOV scheme will not only affect the M1 itself, but also the surrounding area. For example, safety levels on the M1 itself might not improve, but there might be safety benefits on the surrounding network due to traffic being attracted to the M1 rather than using local roads. In that case, the scheme would be likely to show an overall safety benefit.

The objectives listed above are for the introduction of an HOV lane on the M1. The HOV lane will be implemented by widening the M1, but the objectives of the widening itself (e.g. to provide extra capacity) are separate from the objectives of the HOV Pilot scheme, and will be assessed separately as part of the widening scheme. The data collected by the Monitoring Consultant will be a key input to the assessment of the widening scheme.

The detailed objectives can be dependent on the design of the scheme. For example, if it was decided that a permanent 60mph speed limit should be imposed on the M1 J7-10, then it would be more difficult for the scheme to meet its objective of minimising the delay for non- HOV vehicles. On the other hand, the scheme might then be able to achieve a new objective: to reduce noise and emission levels.

4. Scope of Assessment

The M1 HOV Pilot scheme will be assessed by two consultants. The Monitoring Consultant will assess the impacts of the HOV scheme; the Scheme Consultant will assess the impacts of the widening and also the general operation of the HOV scheme, including publicity. The following sections describe the scope of the assessment in more detail.

4.1 Monitoring Consultant

The assessment of the impacts of the HOV scheme by the Monitoring Consultant will cover the following factors:

The effect of the scheme on traffic. The consultant should consider the role of all the following: speeds, flows, journey times, queue lengths, headways, lane utilisation, vehicle classification, vehicle occupancy and travel patterns. Where appropriate, the effects should be determined on a lane-by-lane basis. The effects will be determined over a range of different conditions (e.g. special events, incidents or bad weather). The effect will be assessed both on the motorway itself and on the surrounding network (adjoining motorways and all-purpose trunk roads).
The effect of the scheme on safety. This includes numbers and severity of accidents, and also accident risk. The effect will be assessed both on the motorway itself and on the surrounding network.
The effect of levels of enforcement on compliance with the scheme (in particular, the numbers of rogue vehicles using the HOV lane).
The effect of any changes to the operation of the scheme once it is installed (e.g. to the times of operation, the signing or the physical design).
Feedback from drivers and/or local residents. This will include obtaining information before the HOV lane is installed, such as origin/destination data. This will enable comparisons to be made once the scheme is operational.

These factors will be defined in more detail in the document specifying the Monitoring Requirements for the project.

The assessment by the Monitoring Consultant should also attempt to identify any unforeseen side effects of the scheme. As much data as reasonably possible should be collected prior to the introduction of the scheme, to make it more likely that side effects would be identified. This will also mean that the assessment is flexible enough to allow for changes to the design of the scheme. The extent of the "before" data set will depend on how cost effective it is to collect the data.

The Monitoring Consultant will provide reports describing the results of the above assessment. These reports will be used by the HA for publicity and to answer questions on the operation of the scheme.

All of the data collected to assess the M1 HOV pilot scheme will form part of a notional data set of national traffic data, to be made available to the HA or consultants for other HA schemes.

4.2 Scheme Consultant

The following aspects fall outside the scope of the assessment by the Monitoring Consultant, and are expected to be carried out by the Scheme Consultant for the widening and HOV schemes:

To establish the cost/benefits of the scheme against those predicted in the original business case. The results of the assessment by the Monitoring Consultant will be an essential input into this work. The Monitoring Consultant will provide information on the effects of the scheme; the Scheme Consultant will apply a monetary value to these and (if required) carry out a business case for further roll-out of HOV lanes.
To optimise, as far as possible, the operation of the scheme. This includes the times of operation, the signing, the physical design, and also the levels and methods of enforcement. The Monitoring Consultant will assess the effects of any changes to the operation of the scheme once it is installed, but will not determine the policy.
To assess the effects of widening the M1. A key requirement will be modeling the effects of widening the M1. The widening and the HOV scheme are being implemented simultaneously, and the Monitoring Consultant will be measuring the effects of these changes. The Scheme Consultant will have to estimate the expected effects of widening so that the effects can be disaggregated; modelling is likely to be the most appropriate method of estimating these effects.
To determine the publicity strategy for the scheme (in particular, the publicity prior to the scheme opening).
To assess the effectiveness of the publicity for the scheme and to monitor the press and public response to the scheme.
To assess the maintenance required during operation of the scheme. This includes maintenance of the signs, the road surface and the Variable Speed Limit gantries.
To mitigate any environmental effects of the scheme (e.g. any landscaping effects).
If required, to determine the effects of construction (e.g. additional delays and construction noise).

The Highways Agency will determine the criteria under which the HOV scheme will be deemed a success, and also the criteria under which the scheme might be removed.

4.3 Discussion

In several of the assessment areas, there is no clearcut dividing line between the work of the Monitoring Consultant and the Scheme Consultant. Examples of these are in optimising the operation of the scheme and in dealing with publicity. For the operation of the scheme, the Monitoring Consultant will provide information on how the scheme is operating and analyse the effects of any changes to the operation, but will not be responsible for policy decisions on the operation. However, the Monitoring Consultant can make recommendations on the operation of the scheme.

Similarly, the Monitoring Consultant will provide reports on the scheme, to be used for publicity, but will not be responsible for the publicity itself. Monitoring the press and public response to the scheme could be carried out by either the Monitoring Consultant or the Scheme Consultant. As the Scheme Consultant is responsible for the publicity strategy, it makes sense for them to monitor the press and public response to the scheme.

There will be between a close liaison between the Monitoring Consultant and the Scheme Consultant, including a considerable exchange of information. For example, the data collected by the Monitoring Consultant will be a key input to the assessment of the widening scheme, and the results of the assessment of the widening scheme will be fed back to the Monitoring Consultant to enable them to disaggregate the effects of the widening from the effects of the HOV scheme.

5. Assessment of the M1 HOV Scheme

5.1 Assessment Options

To determine the options for the assessment of the impacts of the M1 HOV scheme, the following factors have been considered:

What are the objectives of the scheme?
How important is each objective, in terms of benefits to stakeholders (e.g. users and the Highways Agency)?
How can the objectives be achieved?
What is the expected impact of the scheme in achieving each objective?
How can the extent to which each objective has been met be measured?
How expensive would it be to carry out the assessment?
How easy would it be to detect any changes that have occurred following the introduction of the scheme

In addition, the assessment of the M1 HOV scheme must consider operational issues for the scheme:

Whether drivers are complying, or if rogue vehicles are using the HOV lane.
Whether drivers are using the scheme properly. This will include an assessment of the proportion of eligible drivers who are choosing to use the HOV lane, and whether drivers understand the signs.

These operational issues will provide an indication of whether the scheme is functioning efficiently, and whether there could be a benefit from modifying the operation of the scheme, e.g. the times of opening, the level of enforcement or the road layout.

When assessing the impacts of the HOV scheme, the Monitoring Consultant must allow for the effect of any changes unrelated to the scheme:

The underlying traffic conditions will have changed during the construction period for the widening scheme. In particular, the widened M1 is likely to attract additional traffic (either from the adjoining network, or new traffic). This information will be provided by the Scheme Consultant.
There may have been physical changes (apart from the widening) during the construction period. For example, the carriageway lighting or the road surface may have significantly changed or new service areas may have been built. The effect of any changes to the adjoining network must also be taken into account.
The assessment should take account of external influences on traffic, e.g. special events, weather conditions and incidents on the surrounding network.
The section of the M1 between Junctions 10 and 13 may be widened during the "after" period for the HOV scheme. Any effects of the widening must be taken into account. On the northbound carriageway, queues might tail back onto the pilot site or one lane might be coned off on the approach to Junction 10. On the southbound carriageway, flows onto the pilot site might be constrained by the presence of the roadworks.
There may be changes in traffic behaviour that are not a direct effect of the scheme. Any national and/or local trends should be obtained by identifying and monitoring suitable control sites.

The remaining effects will be attributable to the HOV scheme. The effect of the scheme may vary on different days, at different times of the day, or for different vehicle types. The effects will also vary in different lanes. The scheme may also have an effect outside the times when it is operational (e.g. drivers might be uncertain whether they can use the lane). The assessment of the scheme should include an analysis of all of these effects.

The widened M1 is likely to have a Variable Speed Limit system installed, which will display reduced speed limits during periods of high flow (see Section 2). It is still to be decided whether a reduced speed limit should be displayed for safety reasons whenever the HOV lane is open. If such a reduced speed limit is imposed, then the effects of this speed limit should be assessed as part of the impact of the HOV scheme. However, if the reduced speed limits are introduced as a result of the widening (i.e. they are due to the normal operation of the Variable Speed Limit system), then the effects of the reduced speed limits should be disaggregated from the effects of the HOV scheme.

Table 1 provides more detail on the objectives of the HOV scheme, and provides information on assessing the extent to which each of these objectives is achieved. For each objective, the following information is provided:

The importance of the objective, in terms of benefits to stakeholders (e.g. users and the Highways Agency). It is classed as High, Medium or Low, relative to the importance of the other objectives. A high importance means that improvements will show a large benefit; a low importance means that improvements may be of little value.
How the objective can be achieved. For the objectives that may have a direct impact, this is a description of how the impact will be achieved. For the operational issues, this is a description of how the information can be obtained.
The expected impact of the HOV scheme in achieving the objective. It is classed as High, Medium or Low, relative to the impacts for the other objectives. A high impact means that a large improvement is expected following the introduction of the HOV lane; a low impact means that any improvement is likely to be small.

Some of the objectives are expressed as avoiding a disbenefit (e.g. "avoid new accident risks"). If the impact is classed as High, it means that it is expected that the HOV scheme will be successful in avoiding the disbenefit. Therefore, a rating of High implies that the scheme will be successful in achieving the objective.

The Importance and Impact information has been assessed subjectively.

Table 1 lists all of the objectives that could be assessed, including Accessibility and Integration objectives specified by WebTAG (shown in italicised typeface). These options for assessment have been reviewed by an independent panel of experts.

Table 1 - Objectives of HOV scheme

5.2 Assessment Strategy

Following discussions with the HA in consultation with an independent panel of experts, it has been decided that all of the options for assessment listed in Table 1 should be included in the assessment strategy, with the exception of the Accessibility and Integration objectives, since these are not directly relevant to the HOV scheme. The effect of the scheme on these objectives will be neutral.

Table 2 provides more information on the assessment of the HOV scheme. It expands on the information in Table 1, providing the following additional information:

How the extent to which the objectives have been met can be measured. This is a list of the types of data that can be collected before and after the scheme is installed. Any differences in the results will show the impact of the scheme on that objective.
The cost of carrying out the assessment (i.e. data collection and analysis). The cost is classed as High, Medium or Low, relative to the costs to assess the other objectives. The cost is an average for the data types.
How easy it would be to measure changes to the data types. The measurability is classed as High, Medium or Low, relative to the measurability of the data required to assess the other objectives. A high measurability means that changes to the data can be easily detected; a low measurability means that changes to the data may not be detected.

The Cost and Measurability information has been assessed subjectively. They are for a "before" and "after" study combined. In some cases, it will be cheaper and easier to measure performance indicators in the "after" period, when additional data sources (e.g. MIDAS data) will be available.

Some of the performance indicators are quantitative (e.g. flows and speeds) and some are qualitative (e.g. driver surveys and opinions of emergency services). In general, the quantitative measures are less costly to collect than the qualitative measures, and any changes are easier to detect.

There is a trade-off between the amount of data that is collected and the cost of collecting the data. For example, when determining the amount of data to be collected from the adjoining road network, a large amount of data is potentially desirable. The impacts of the HOV scheme will become less apparent as the distance from the M1 pilot site increases. At some point, it is not cost effective to collect the data.

In addition, the effect of the scheme on safety on the surrounding network will be difficult to measure. Accident rates at the junction roundabouts could be monitored. Apart from this, there would be too many unknown variables for any safety study on the wider surrounding network to identify a significant change in safety (or even to provide an indication of side effects on safety from direct measurement). It is recommended that flow levels on the wider surrounding network should be used as a proxy for safety. If there is a change in traffic levels using the surrounding network following the introduction of the HOV scheme, then this would be likely to have an impact on safety. The Local Authority may be able to provide some flow and accident data for the surrounding network. In addition, flow levels joining and leaving the motorway will provide some information on flows on the surrounding network.

Table 2 lists all of the objectives that could be assessed. The objectives to be assessed by the Monitoring Consultant are shown in Table 2 in black typeface. A few objectives are outside the remit of the Monitoring Consultant and are likely to be the responsibility of the Scheme Consultant rather than the Monitoring Consultant (see Section 4); these are shown in Table 2 in red italicised typeface.

The results of the assessment by the Monitoring Consultant will provide the information to be used by the Scheme Consultant to achieve the objectives for which they have responsibility.

Table 2 - Assessment of HOV scheme

The impacts of introducing an HOV lane will be assessed by the Monitoring Consultant by comparing the "before" and "after" data collected. The comparison in the "after" period will be against the expected effects of simply widening the M1 (i.e. not implementing an HOV lane). The anticipated effects of widening the M1 will be determined by modelling; it is envisaged that this modelling will be carried out by the Scheme Consultant as part of the widening work.

Overall flow levels and travel patterns in the M1 corridor may change during the construction period (this is anticipated to last for 3 years), and these must be taken into account during the monitoring. Changes in flow levels and travel patterns will be determined by the Monitoring Consultant, probably via Origin/Destination surveys.

Underlying changes in traffic behaviour between the "before" and "after" periods should also be taken into account. Changes might have occurred in vehicle occupancy, lane discipline, accident rates and overall traffic speeds. In addition, there will be a general traffic growth from year to year. To obtain information on the underlying changes, it is recommended that several Control Sites should be monitored. The Monitoring Consultant should identify suitable Control Sites. The Control Sites should have similar characteristics to the M1, should be in the South-east (as driver behaviour varies across the country), and should be far enough away from the M1 not to be affected by the widening or the roadworks.

5.3 People affected by the scheme

For every traffic scheme, there are people who would gain and people who would lose (or perceive themselves to lose) from the introduction of the scheme.

The people who perceive disbenefits are likely to be the people who object to and complain about the scheme. The assessment strategy should consider how the results of the assessment could be presented to address the concerns of these people. For the M1 HOV scheme, it is recommended that:

Estimates should be made of the disbenefit to specific groups and of the overall benefit, in advance of the scheme becoming operational. Advance publicity should mitigate the effect of the scheme on the people who perceive disbenefits.
Any disbenefits to specific groups should be calculated once the scheme is operational. These results could then be used to counter complaints from this group. It is likely that they would perceive themselves as suffering greater disbenefits than is actually the case. In fact, they may not be suffering disbenefits at all, just not benefiting by as much as other users.

The gainers and losers could be specific stakeholder groups or subsets of these groups. (Stakeholders are people who may be affected by a new scheme.) The stakeholder groups for the M1 HOV scheme are:

Private car users
Business users
HGV users
Bus and coach users
Motorcycle users
Residents (surrounding areas)
Local businesses (including hotels)
Authorities
- Ministers
- DfT
- HA
- Local Authorities
- Regional Planning body
- Scheme Consultant
Police
Emergency Services
Automobile Association and RAC
Regional Control Centres
Freight hauliers
Bus and coach operators
Rail operators
Luton Airport authority
Environmental agencies and interests
Road maintenance contractors

For the M1 HOV scheme, the main groups of people who will gain are drivers and occupants of HOVs. They will have reduced delays and their journey time reliability will also improve.

The main losers will be drivers of single occupancy vehicles. They may have increased delays and their journey time reliability may also deteriorate. In addition, the Police may feel that enforcement of the HOV lane is not an effective use of their time. People who may perceive a disbenefit could include drivers who are confused by the additional signing or who object to control measures in general.

It is recommended that opinions should be sought from relevant stakeholder groups, both before and after the scheme is installed.

2. Influencing travel behaviour will be achieved via the means listed under the other subject areas in Table 1. back [2]

3. The influence of the HOV scheme on travel behaviour will be assessed via the other methods listed in Table 2. back [3]

6. Publicity

The M1 HOV scheme will have a high public and media profile. It will be important to have an integrated approach to publicising the scheme and disseminating the results of the assessment of impacts.

It will be important to inform the press and the public of the reasons for the scheme and its expected effects, before the scheme is installed. It is recommended that advance publicity should explain the reasons for implementing the scheme and its expected impact.

Any likely negative impacts should be dealt with in the advance publicity, to attempt to reduce the dissatisfaction felt by any people who perceive disbenefits from the scheme. The prior publicity should not oversell the idea or inflate anyone's expectations.

It is also important to set up a method for responding quickly to criticisms in the press or by MPs. This highlights the need to be aware of the scheme's potential impacts so that appropriate information may be collected and presented in support of the scheme. Suitable data should be processed quickly, especially during the first few weeks of operation of the scheme, as this the most likely time for criticism.

The success of the scheme will also need to be conveyed to the public and the media. This should help both to prepare the public and to gain their approval for the wider implementation of the techniques concerned. Initial results should be released as soon as possible after the introduction of the scheme, followed by a more substantial report when detailed results are available. The initial results should concentrate on general effects of the scheme; care should be taken when quantifying benefits as the early results may change as more data becomes available. Any early publicity should have strong caveats attached to any results, whether they are positive or negative. There should be sufficient data available after six months of operation for a publicity release summarising the impacts of the scheme.

A review of existing HOV schemes (Dixon and Alexander, 2005) found that it is important that the public be given a complete picture of any benefits or disbenefits as, for some American schemes, incorrect conclusions have been drawn from published articles where incomplete data has been given. This lack of data was interpreted as a cover-up by the local authorities, who were thought of as trying to hide disbenefits of a scheme.

The most suitable methods of disseminating information are still to be determined. Possible methods are leaflets to be distributed locally (e.g. at libraries and service areas), and items in the local and national press and on television. Use of video techniques may make the information more comprehensible to the general public.

7. Conclusions and Future Work

This report has listed the objectives of the M1 HOV Pilot scheme, and has considered how to assess the extent to which each of these objectives has been achieved.

Possible methods of assessing the objectives of the scheme have been listed. This list provides options for assessment, which have been used to recommend an assessment strategy to determine the impacts of the M1 HOV scheme on traffic. The strategy also includes an assessment of the operation of the scheme (e.g. the effects of enforcement on compliance with the scheme).

Some of the assessment falls outside the scope of the specification for the Monitoring Consultant, and is expected to be carried out by the Scheme Consultant for the M1 Widening and HOV schemes. This includes determining the publicity strategy for the scheme, optimising the operation of the scheme and establishing the cost/benefits of the scheme.

The options for assessment and the recommended assessment strategy have been reviewed by an independent panel of experts.

The next stage of this work package is to use the assessment strategy described in this document to develop a draft of recommended monitoring requirements for the M1 HOV Pilot scheme. This will include:

A definition of all data to be collected.
The locations at which the monitoring will be conducted.
The periods for which "before" and "after" data are required.
The target statistical accuracy for each data item.
The speed with which the results are required.

8. References

Dixon C & Alexander K (2005). Literature Review of HOV Lane Schemes. Unpublished Report UPR/T/002/05. TRL Limited, Crowthorne, UK.
Minutes of HOV Objectives Workshop 6th December 2004. Network Strategy, Highways Agency.
Powell G (2001). Guidelines for the monitoring and evaluation of pilot projects. Guidance Note, TSE TAME, Highways Agency.
Rees T R (2005). Review of Objectives for the M1 HOV Pilot. Unpublished Report UPR/T/007/05. TRL Limited, Crowthorne, UK.
Transport Analysis Guidance (WebTAG). http://www.webtag.org.uk/, Department for Transport.

Highways Agency - Safe roads, Reliable journeys, Informed travellers