Smart Motorways: What Are They and How to Use Them

The UK was the first country to introduce smart motorways in 2006. However, more countries, including the US, have borrowed the idea. An example of smart motorways in the US is the recently completed three-mile stretch of I-94 in Michigan. It provides real-time data about traffic, weather, and road conditions. However, there are plans to use a technology that will let it communicate directly to vehicles traveling on it.

Smart motorways are a great way to manage congestion without expanding road capacity through traditional means like widening lanes. However, they operate differently from conventional motorways, so drivers used to traditional motorways may find them confusing. But don't worry. This guide will cover everything you need to know about smart motorways, from what they are to how to use them.

What is a smart motorway?

A smart motorway is a section of a highway or major road that uses advanced traffic management technologies to regulate traffic flow, improve safety, and optimize road capacity. In contrast to traditional motorways, which rely on static features like fixed speed limits, smart motorways use real-time data and automated systems to make dynamic decisions that adapt to current road conditions.

The concept originated in the UK in the early 2000s, and since then, many countries, including the US, have started implementing their own versions of smart motorways. These roads employ technologies like:

• Variable speed limits: Speed changes depending on traffic conditions, weather, and accidents.
• Electronic signage: Overhead and roadside signs inform drivers of lane closures, speed limits, and potential hazards.
• Hard shoulder running: In some types of smart motorways, the hard shoulder can be temporarily converted into an additional lane during periods of high traffic.

The overarching goal of smart motorways is to increase road capacity without physically expanding the highway, reducing the need for extensive construction projects and land usage.

Types of smart motorways

Smart motorways come in three main types, each offering different levels of traffic management and control:

Controlled motorways

Controlled motorways are the most basic form of smart motorways. The hard shoulder remains in place on these roads for emergency use, but variable speed limits are applied to improve traffic flow and manage congestion. These limits are displayed on overhead signs and are monitored by traffic control centers.

Dynamic hard shoulder running

Dynamic hard shoulder running motorways allow for the temporary use of the hard shoulder as an additional traffic lane. When traffic is heavy, overhead signs notify drivers that they can use the hard shoulder as a lane.

When not in use, the hard shoulder reverts to its primary role as a space for breakdowns or emergencies. However, safety concerns have arisen with this type of motorway, as drivers in an emergency may not have immediate access to the hard shoulder.

All-lane running (ALR)

All-lane running motorways are the most controversial type of smart motorways. On these motorways, the hard shoulder is permanently converted into a running lane, meaning no dedicated emergency lane exists.

Emergency refuge areas (ERAs) are positioned at intervals, offering a space for vehicles that need to stop in an emergency. These motorways are designed to maximize road capacity, but they have faced criticism for potentially putting drivers at risk in the event of a breakdown.

How smart motorways work

Smart motorways rely on cutting-edge technologies and infrastructure to monitor real-time traffic and make automated decisions. These systems operate based on data collected from sensors, cameras, and other monitoring equipment installed along the road.

Key technologies

• Traffic sensors: Sensors are installed beneath the road surface to detect the speed and density of traffic. They provide vital information about congestion, allowing the system to adjust speed limits accordingly.
• CCTV cameras: High-definition cameras monitor the road for incidents, such as accidents or breakdowns. Traffic management centers can respond quickly to incidents, deploying emergency services or adjusting speed limits to protect stranded vehicles.
• Variable message signs (VMS): These overhead and roadside signs communicate important information to drivers, such as speed limits, lane closures, and alerts about upcoming hazards. These messages can change in real time based on traffic conditions.
• Ramp metering: This system controls the flow of vehicles entering the motorway from slip roads. By limiting the number of cars that can merge onto the motorway, ramp metering helps prevent congestion at busy junctions.
• Emergency refuge areas (ERAs): On motorways where the hard shoulder is done away with, ERAs provide a safe place for vehicles to stop in case of breakdowns or emergencies. These areas are equipped with emergency telephones and are spaced at intervals of about 1.5 miles (2.5 km).
• Automated lane controls: These manage the use of hard shoulders as additional lanes during peak hours.
• Connected vehicle technology: This smart motorway technology facilitates communication between infrastructure and vehicles, enabling smoother traffic flow.

Real-time traffic management

The real-time data collected by the technologies above is fed into regional traffic management centers and analyzed by sophisticated software systems. This analysis drives automated decisions, such as adjusting speed limits or opening and closing lanes. Human operators can also intervene if necessary, such as in an accident.

One key benefit of this dynamic system is its ability to respond immediately to changing conditions. Speed limits are reduced if traffic starts to build up to smooth the flow and prevent bottlenecks. If a car accident occurs, lanes can be closed, and drivers rerouted without delay.

Advantages of smart motorways

Smart motorways offer several benefits over traditional motorway designs. Some of the key advantages include:

Improved traffic flow

Smart motorways can prevent the stop-and-go traffic that often characterizes congested roads by dynamically adjusting speed limits and utilizing all lanes. Smoother traffic flow reduces travel times and decreases the likelihood of rear-end collisions caused by sudden braking.

Increased road capacity

Instead of physically widening roads, smart motorways increase capacity by optimizing the use of existing infrastructure. This is especially important in densely populated areas where land for road expansion is limited. By opening the hard shoulder to traffic during busy periods, smart motorways can accommodate more vehicles without the need for costly and time-consuming construction projects.

Reduced emissions

Smoother traffic flow reduces emissions, as vehicles are less likely to be stuck in stop-start traffic. This contributes to lower carbon emissions and improved air quality, aligning with environmental goals in many countries.

Lower costs

Smart motorways are more cost-effective than building new roads. They require less land acquisition, construction, and maintenance compared to traditional methods of road expansion.

How do smart motorways compare to traditional motorways?

• Road capacity: Smart motorways can handle more vehicles by using all available lanes, including the hard shoulder during peak times. Traditional motorways lack this flexibility.
• Traffic management: Smart motorways use real-time data and technology to adjust traffic flow, while traditional motorways typically have fixed speed limits and rely on physical interventions, such as traffic police, to manage incidents.
• Safety: Traditional motorways have a hard shoulder, providing a dedicated space for emergency stops. Smart motorways often do not, raising safety concerns despite the Emergency Refuge Areas (ERAs) and the use of technology to mitigate risks.

Concerns regarding smart motorways

Smart motorways have come under significant scrutiny despite their benefits, particularly concerning safety.

Safety concerns

The most contentious issue with smart motorways is the removal of the hard shoulder. Critics argue that drivers are at greater risk of being hit by other vehicles since there is no dedicated space for breakdowns. Although Emergency Refuge Areas (ERAs) are provided, they are not always spaced closely enough for drivers to reach them safely.

Incident response times

In some cases, slower response times have exacerbated accidents and breakdowns on smart motorways. While traffic management systems are designed to detect incidents quickly, critics argue that relying on technology is not always as effective as having physical safety measures like a hard shoulder. Reports of vehicles stranded in live lanes for extended periods have increased the risk of secondary collisions.

Public perception and trust

Public opinion on smart motorways has been mixed. While some drivers appreciate the benefits they can offer, others have expressed concerns about safety, particularly with the removal of the hard shoulder.

Smart motorway driving rules

Driving in a smart motorway can be daunting, especially for young drivers. Here are a few rules you need to be aware of when driving on smart motorways.

• Follow the speed limit displayed on the overhead electronic signs.
• A red X above a lane indicates that the lane is closed, even if it is the hard shoulder. Driving in a closed lane is illegal and can result in penalties.
• Head for the nearest Emergency Refuge Area if you experience a breakdown or emergency on a smart motorway with no hard shoulder. These are clearly marked and spaced about 1.5 miles (2.5 km) apart.
• Keep left unless you are overtaking slower-moving traffic. Use the right-hand lanes only for overtaking and return to the left lane when done.
• Be alert for updates via overhead signs.
• Even though smart motorways are designed to manage traffic flow, it's important to always drive at a speed suitable for the current conditions, such as rain, fog, or heavy traffic.

Conclusion

Smart motorways offer a glimpse into the future of transportation, where real-time data, automation, and dynamic systems work together to create safer, more efficient road networks. They help improve traffic flow and increase road capacity.

That said, getting additional driving experience is one of the best ways to boost your driving confidence in smart motorways. A further driving qualification could make you a safer and more confident driver, and it might even reduce your auto insurance premium.