Analysis: Of speed and its limits

02/05/2018
Dom Browne

One of the key aspects of innovation is that you can't be afraid of (safety monitored) trial and error. Every bold step forward requires a background of missteps and not-quite-perfect attempts.

In the era of big data and computer learning, this process is happening all around us all the time with many systems evolving and adapting with use in real-time.

It is within this context that the news that Highways England will be carrying out a 'comprehensive review' of variable speed limits on motorways, after admitting that lower limits were not always correctly set, is to be welcomed.

”Local
 

Highways England chief executive Jim O’Sullivan explained that 40, 50 or 60mph limits were being set as a preemptive measures when congestion was expected to mount on ‘smart motorways’ in England, using predictions about traffic levels.

He also admitted that there was ‘dissatisfaction’ among some motorists when the expected build-up failed to materialise, forcing them to drive slowly along free-flowing roads

As Highways understands it, part of this issue is likely to be because the system is working well to prevent the predicted congestion and part of it is because the system is, understandably, not quite perfect yet and speed restrictions are being triggered for the wrong reasons or maintained for too long.

Highways England has done the right thing in being open about this and the review is not just as good news for drivers, but good news for professionals and the systems they seek to refine.

Highways received a briefing on the background to this, which demonstrates some of the complexity that goes behind this issues.

Highways England traffic officers have control over a manual system on smart motorways, which have variable speed limits and the potential to open the hard shoulder for all lane running. These officers are directly responsible for core tasks like opening up a hard shoulder.

However there are also elements to the variable speed limits system that operate under an automatic algorithm system for regulating speed. Apparently anomalies on the network, such as a particularly slow moving car, can lead to the automatic system being triggered and unnecessary speed restrictions being put in place for unnecessary amounts of time.

Traffic officers are being trained in how to spot and override this, while the review could help evolve the background system and its algorithm.

Highways England did a piece of research and trial analysis looking at traffic flow on the strategic road network in the North East from February to March this year compared with February to March last year.

The research highlighted some of the issues with the algorithm system that need further development, hence the comprehensive review.

The review could take 12 months over this financial year and would take into account next February and March's data and hopefully provide enough information to tweak and finesse the automatic algorithm system for regulating speed.

However Highways England stressed this will be an ongoing process, as the government-owned company seeks to take away driver frustration as and when it arises.

Highways England executive director of operations Nick Harris said: 'Variable speed limits help keep drivers moving by smoothing the flow of traffic and improve safety for all road users. We have trialled an improvement to the signal settings to reduce the length of time these are set to help restore the national speed limit quicker to further improve journeys.'

One issue that needs to be considered alongside this is speed enforcement. 

Data obtained under by the Times under Freedom of Information showed that 72,348 people were fined on motorways with variable speed limits last year. This was almost double the number a year earlier and a tenfold rise in five years. Of those, two thirds of fines were imposed on motorists driving at 69mph or below, even though the national speed limit is 70mph.

This suggests that the majority of people are being fined for speeding when variable speed limits have been put in place. One potential solution to this is the introduction of average speed cameras along certain routes.

Average speed cameras do not currently operate on smart motorway sections, i.e. where the speed varies.

The system has worked well on the A9 in Scotland, and despite the usual initial concerns over over-zealous enforcement, the use of average speed cameras has been celebrated by Scottish ministers as a major step forward in road safety. 

It might make a nice irony if they also saw people fined less on English motorways.

Highways jobs

Highways Estimator

Ringway
Competitive Salary
As the Highways Estimator you will join a busy environment and become an integral part of the team. Hounslow (London Borough), London (Greater)
Recuriter: Ringway

County Highways Manager

Lincolnshire County Council
£55,503 - £60,578
Seeking a highly motivated leader and an excellent communicator, who has a proven ability to build relationships and trust, leading by example. Lincolnshire
Recuriter: Lincolnshire County Council

Local Highways Manager (East) - Lincolnshire County Council

Lincolnshire County Council
G12 £43,662 - £50,430
Seeking someone who combines excellent technical knowledge with a dedication to the customer. Lincolnshire
Recuriter: Lincolnshire County Council

Assistant Director (Planning, Regeneration & Transport)

Rotherham Metropolitan Borough Council
£87,791 per annum  
This is an exciting time to join Rotherham and make a real difference. We are looking for an outstanding Assistant Director who will bring... Rotherham, South Yorkshire
Recuriter: Rotherham Metropolitan Borough Council

Corporate Director

Islington London Borough Council
Up to £135k
You will share our values and be passionate about helping us shape the Islington of the future. Islington, London (Greater)
Recuriter: Islington London Borough Council

Assistant Engineer

Cambridgeshire County Council
£21,074 - £30,756
Looking for strong team players interested in working with a variety of professional and community partners across Cambridgeshire. Cambridgeshire
Recuriter: Cambridgeshire County Council

Junior Energy Manager Apprentice

Brent Council
£15,000 p.a. inc.
The right person for this job will be pro-active and innovative in finding a way forward. Wembley, London (Greater)
Recuriter: Brent Council

Career Grade Drainage Engineer

Swindon Borough Council
£19,092 to £40,680 p.a
Working in the asset management team, you’ll support the work of the Lead Local Flood Authority (LLFA) and Highways Authority. Swindon, Wiltshire
Recuriter: Swindon Borough Council

Highway Construction Project Manager

Brent Council
£50,442 - £53,526 p.a. inc.
We are looking for an accomplished highway construction project manager to support the delivery of two high priority highway schemes. Brent, London (Greater)
Recuriter: Brent Council

Traffic Signals & UTMC Manager

Bristol City Council
£42,683 - £45,591
Looking for someone with proven management experience, enthusiasm, creativity, vision and good communication skills. City of Bristol
Recuriter: Bristol City Council

Principal Highways Project Engineer

Knowsley Metropolitan Borough Council
£34,106 - £35,229 per annum
The post holder will be responsible for project managing the delivery of two highway projects on the Key Route Network. Knowsley (Metropolitan borough), Merseyside
Recuriter: Knowsley Metropolitan Borough Council

Traffic Schemes Officer

Oxfordshire County Council
£22,021 - £29,636 per annum
An exciting opportunity has arisen to play a central role with the Traffic Team in the maintenance of the highway network... Kidlington, Oxfordshire
Recuriter: Oxfordshire County Council

Traffic Engineer

Telford & Wrekin Council
£29,055 to £30,756
This is an exciting opportunity to join Telford & Wrekin Council’s Traffic Management Team! Telford, Shropshire
Recuriter: Telford & Wrekin Council

Assistant Engineer – Traffic Regulation

Telford & Wrekin Council
£23,866 to £25,463
This is an exciting opportunity to join Telford & Wrekin Council’s Traffic Management Team. Telford, Shropshire
Recuriter: Telford & Wrekin Council

Environment Officer

Kirklees Metropolitan Council
£29,909 – £32,233 Grade 11 - £33,136 - £35,229
All Environment Officers lead, project manage and/or co-ordinate large environmental projects... Huddersfield, West Yorkshire
Recuriter: Kirklees Metropolitan Council

Highways Quantity Surveyor

Leicester City Council
£30,756 - £33,136 pro-rata per annum
Working in the Highways Maintenance Group, you will be responsible for the operational highway maintenance activities Leicester, Leicestershire
Recuriter: Leicester City Council

Highways Engineer/Inspector

Royal Borough of Greenwich
£22956 - £32637 per annum
Highways Engineer/Inspector - PermanentThere are plenty of reasons to take a closer look at Royal Greenwich.Royal Greenwich is undergoing a huge trans England, London, Woolwich
Recuriter: Royal Borough of Greenwich

Engineer - Bridges

Cambridgeshire County Council
£32,825 - £35,401
We have a vacancy for a Structures Engineer working within the Bridge’s team! Cambridgeshire
Recuriter: Cambridgeshire County Council

Engineer

Cambridgeshire County Council
£32,825 - £35,401
You will be required to lead the delivery of a wide range of highway improvements and maintenance projects... Cambridgeshire
Recuriter: Cambridgeshire County Council

Assistant Director, Highways Operations

Hertfordshire County Council
Competitive Salary
Ensuring the transport infrastructure reflects the pace of our developments and growth agenda... Hertford, Hertfordshire
Recuriter: Hertfordshire County Council

Download your Highways App

Google App Apple App

Highways on Fridays

Latest Issue

latest magazine issue

Includes:

  • The view from the regions
  • Essential Brexit analysis
  • Traffex and Parkex preview
View the latest issue

Latest Video