ITS service definition
Hard Shoulder Running (HSR) enables the dynamic temporary use of hard shoulders at road sections, including at junctions with the aim to increase road capacity when necessary. Hard Shoulder Running could be considered similar to the creation of an extra lane, but with specific safety issues due to the fact that a hard shoulder in common understanding is not available for general traffic use, and is sometimes replaced by refuges where road users can stop in an emergency or in case of breakdown.
Hard Shoulder Running is triggered by traffic demand, at fixed times or due to automated or manual requests and applied typically to bottlenecks, locations with poor safety records with a recurrent – but not constant – lack of capacity.
ITS service objective
The objective of Hard Shoulder Running is to increase road capacity on a section of the road network necessary, in order to minimize (heavy) congestion and to reduce the probability of congestion caused by incidents.
ITS service radar
ITS service key words
The hard shoulder running service enables dynamic temporary use of hard shoulders.
Hard Shoulder Running should only be implemented when the safety level remains the same or improves against the current operational mode. It can be applied on network areas, route sections and junctions prone to capacity problems. The capacity problems can be on a regular basis (e.g., Tuesday versus Friday, peak hour versus off peak hour) or for a longer period (major road works). The Hard Shoulder Running should cover the entire bottleneck, thus start at a junction with major entering flows and end at a junction with major flows leaving the road. Otherwise, the roads upstream and downstream of the HSR section may need to cope with extra capacity requirements as a result of potential higher demands.
The measures must include strict safety precautions in order to maintain the existing safety levels and can only be deployed if specific criteria are met, such as “no expected increase in emission levels”.
In a normal situation a hard shoulder has a specific set of users, mainly road users in emergency/ breakdown situations. Opening the hard shoulder to all road users can cause problems for emergency users and therefore their needs must always be considered.
Opening the hard shoulder for regular traffic without additional measures could give the hard shoulder an ambiguous character. This can cause confusing situations for road users, some examples of which include:
Good unambiguous instructions and education can counter these problems.
The vision for use of Hard Shoulder Running is to increase road capacity on a necessary section of the road network, in order to minimize (heavy) congestion and to reduce the probability of congestion caused incidents. The level of throughput of traffic should increase due to the increase in road space.
The mission for Hard Shoulder Running:
Hard Shoulder Running is similar to creating a dynamic extra lane triggered by traffic demand, at fixed times (peak hours) or even manually, and therefore requires dynamic traffic management control (see also TMS-01 Dynamic lane management). This extra lane is also to be controlled in the case of the use of the hard shoulder by a broken-down vehicle.
In specific cases Hard Shoulder Running:
Hard Shoulder Running is a special application of dynamic lane management. As a special service it interacts with the following other European ITS Core services:
Note: By applying Hard Shoulder Running, incident warning and management becomes very important and can become more complex. In this instance an extra step in the incident warning and management process is needed, i.e., to check if the hard shoulder is clear or can be cleared prior to opening of the hard shoulder to traffic. This also applies to ensure that proper winter maintenance has been carried out at winter time before opening the hard shoulder.
Hard Shoulder Running enables the temporary use of hard shoulders along road sections. To achieve this overhead signals or signs at the roadside at regular intervals are used to indicate whether a hard shoulder is open for normal traffic. Furthermore, variable message signs are used to inform road user of current traffic conditions and in most cases the imposition of reduced speed limits which can be mandatory. Furthermore, lane signals at regular intervals – if present – can be used to indicate whether a hard shoulder is open for normal traffic.
Hard Shoulder Running is triggered automatically by traffic demand, at fixed times or due to manual requests and applied to bottlenecks, locations with poor safety records with a recurrent – but not constant – lack of capacity.
Figure 65 shows the typical functional architecture and control flow of a “Hard Shoulder Running Service”.
Hard Shoulder Running is carried out with a control algorithm or by using a manual request according to pre-determined traffic conditions such as high traffic demand.
Hard Shoulder Running is carried out via the following (illustrated by examples) processes:
If a lane control system is available, active signage above each lane and the hard shoulder should be used. A symbol, such as a green arrow pointed downward and/or variable speed limit signs identifying open lanes and the allowed maximum speed, respectively, equally indicate that the hard shoulder is open for use; however, these symbol types (e.g. arrows or speed limits) cannot be used interchangeably at one location. Activated overhead signs dynamically indicate the total number of open lanes and whether the hard shoulder is open for use as an additional lane. Another option is the use of dynamic roadside signage to provide road users with instructions that the hard shoulder is open for use. Either option can be used or both can be used simultaneously to support the dynamic signage inform road users that the hard shoulder can be used for driving.
Traffic monitoring and decision
Before implementation of a Hard Shoulder Running traffic management services a feasibility study will be able to answer the following questions:
Hard Shoulder scheme evaluation
Following implementation of an HSR scheme, evaluation of the scheme will indicate how successful the scheme has been and whether the HSR services should be expanded other otherwise.
To measure the impact of Hard Shoulder Running on safety, network efficiency and environment, it is necessary to collect data from the scheme using a proven methodology.
Suggested data for evaluation:
In general, it is necessary for national and European law and legislation to allow for the use of hard shoulders (AGR- European agreement on international main arteries, Annex II, section III.3.2).
Per Member State different organisational standards and guidelines are used for hard shoulder measures. This does not necessarily affect the uniformity of the service for the road user.
Common Look & Feel requirements:
Common Look & Feel advice:
Hard Shoulder Running signage
Note: In some cases, the use of static signs can be sufficient. This is an option for Hard Shoulder Running that is used at set times (i.e. weekdays – 7:00-9:00)
Information provision standards:
Table 32 gives the Level of Service recommendations for a Hard Shoulder Running service. The background of this concept is descripted in chapter 2.6.
Table 32: Level of Service recommendations for Hard Shoulder Running
Level of service requirement:
Table 33: Level of Service to Operating Environment mapping table (see also chapter 2.5.3 and ANNEX C)