The ultimate comparison between steel and composite road plates

Road plates are often used in the civil and roading infrastructure industry to temporarily cover a trench, hole or other disrupted area. In this blog we compare the conventional steel road plates to our composite road plates, to help you decide which option works best when you’re after an efficient, safe and cost-effective solution to cover excavations!

To ensure the required infrastructure and services are provided for our communities, civil works such as pipe repairs, stormwater or drainage pipe installations, water and gas connections or fibre connections are a regular occurrence. As these projects involve underground works, it’s common for roads, driveways and footpaths to be excavated to allow the tasks to be carried out.

Works such as these can be a costly and time-consuming exercise that typically results in traffic disruptions for commuters. While these are often planned for a time when the traffic flow is lighter, disturbances are often unavoidable, especially for long term projects. Road plates are often installed to allow the flow of pedestrian and/or vehicle traffic to continue during the project, rather than having to restrict access.


Steel road plates have been around for a long time to provide access over excavations. They’re particularly useful for larger excavations as steel plates are known for their strength. However their heavy weight means that mechanical lifting is often required to install and remove these plates, making the process both hazardous and time-consuming.

Fibreglass road plate

Modular, composite road plates offer a faster, safer and easier alternative to traditional heavy steel plates. Vanguard supplies composite road plates manufactured in the UK by an innovative and well-known manufacturer; Oxford Plastics. Recently, improvements have been made to the Low Pro 2300 x 500mm road plates; these are now engineered and tested to handle 44T vehicles over a 1200mm trench span. These new composite plates have the strength to withstand heavy vehicles, while at the same time being lightweight enough for a two person lift, as demonstrated by contractors in this installation video.

When evaluating which type of road plates are best to use, there are several factors to consider, such as:

  • Upfront and operational costs
  • Safety
  • Ease of use
  • Environment
  • Installation and removal methods

Below we explore the pros and cons of composite and steel plates in each of these areas, to see how both options stack up.

Modular road plates

Upfront & Operational Costs

Typically steel plates are relatively affordable to purchase, whereas composite road plates can be more expensive upfront. However, due to their heavy weight, steel plates typically need to be transported to site and unloaded by a Hiab or crane truck, and then moved around with machinery such as diggers. Composite modular road plates don't require any extra equipment to install or remove and can simply be hand-lifted into place on site by two people. The time savings alone mean fewer hours wasted with transport and handling of the plates, resulting in more operational time getting the job done.

This increased efficiency provides cost savings compared to steel plates - less machinery required, less time to install, therefore less traffic management costs. This faster process also results in roading disruptions being kept to a minimum.

Additionally, steel road plates require cold mix asphalt around all the edges to provide a ramp for vehicles, which means additional costs of material and time involved to pour the asphalt on site. Composite road plates have rubber end sections which eliminates the need for cold mix and further reduces the installation time.Because time on site equals money, watch this video testimonial of a USA civil contractor explaining the operational costs they saved by using composite plates.


Steel plates have long been known for their strength and capacity to handle vehicles. However, they are also prone to bend and degrade over time. This is especially common with frequent heavy loads or when the weight rating of the steel plate is unknown and used incorrectly. 

Vanguard’s composite road plates are tested to specific weight ratings, and include guidance on each plate stating the maximum trench span and weight load they are approved for, which helps to ensure the plates are used within their limits and are not damaged with incorrect use.

Composite road plate


Steel road plates tend to make a loud clunking noise when vehicles pass over top of them, which can be frustrating for those living or working near the installation site. On some projects, contractors can even be penalised for excessive noise pollution. In comparison, composite road plates have rubber edges which dampen road noise significantly, making them suitable for residential areas and helpful for keeping neighbours on-side!

Steel road plates


Many steel road plates can be very slippery if not covered with an anti-slip coating, especially when wet. This hazard has been the cause of multiple cyclist injuries and fatalities around the world. Vanguard’s composite road plates have an anti-slip surface that is evaluated through the British Pendulum Test to ensure cyclists and vehicles are safe to cross. 

Steel road plates typically need to be put into place with lifting machinery, which not only takes longer but adds another hazard on-site, with heavy steel plates swinging through the air or being dragged along the ground. Composite road plates are lightweight and much easier to install and manually manoeuvre by two people, eliminating the risk of airborne plates and reducing the chance of incidents. 

Interlocking modules road plate

Composite road plates have a unique interlocking system - each module has a steel linking pin which connects to the following module on an angle, and locks into place when lowered flat (as demonstrated in the image above). This interlocking system means it is impossible for plates to pull apart unless they are lifted on an angle and disengage, making it much safer and more secure than steel plates.

Composite road plates also have additional visual safety cues. The bright yellow surface visually alerts motorists as they approach the worksite and the speed hump profile also helps to slow vehicle speeds, making it safer for workers in the worksite.

Modular road plates - civil works

Ease of Use & Installation

Steel plates are made in large rectangular forms which means they don’t conform well to the contours of roads, especially in narrow streets where the surface slopes significantly from side to side. If steel plates are not placed and secured correctly on the road, they can shift around and become a dangerous hazard on the road. In comparison, composite plates are made up of modular sections which means they adapt to the curves in the road and do not create any uneven surfaces.

Vanguard’s composite road plates also have a drop-pin securing system which consists of steel drop-pins that lock up against the  trench wall. This feature means there is no chance of the plates dislodging from their position. 

Secure road plates

Steel plates still have a role to play in today’s world, as they are the only option for covering large excavations to provide vehicle access. However, in certain situations such as smaller excavations, composite plates have a number of operational and safety advantages, which make them a better option for contractors to use. For more information on this product, we recommend downloading the Low Pro Road Plate 2300 x 500 spec sheet.

Alternatively, if you would like to discuss composite road plates further with one of our product specialists, please contact us on the form below and we’ll respond within 60 minutes!