Product Description

Height Restriction Ahead – W320 Road Sign

The W320 Height Restriction Ahead road sign is a warning sign used to alert drivers that the available vertical clearance above the roadway is restricted ahead.

The official South African designation is HEIGHT RESTRICTED. W320 is used where a height gauge associated with a railway crossing or an overhead structure creates a restricted clearance for vehicles.

The sign is particularly important for trucks, buses, trailers, caravans, delivery vehicles and other high vehicles that may exceed the available clearance.

What Does the W320 Road Sign Mean?

W320 means Height Restricted. It warns road users that the vertical clearance ahead is limited.

The restriction may relate to:

• A height gauge at a railway crossing with overhead electrical power cables
• An overhead bridge or other structure
• Another overhead obstruction where the available clearance is restricted

W320 provides advance warning. The actual height limit at the restriction is shown by the applicable R204 Height Limit regulatory sign.

When Is W320 Used?

The South African Road Traffic Signs Manual states that W320 should be displayed in advance of a height gauge or overhead structure when the clearance over any portion of the roadway is less than 4.7 m.

This means W320 is not simply a general warning for every bridge or overhead structure. It is specifically associated with restricted vertical clearance.

What Does Vertical Clearance Mean?

Vertical clearance is the available height between the highest point of the roadway and the lowest point of the overhead obstruction.

For a vehicle to pass through the restriction, the vehicle and its load must remain within the available clearance.

Drivers should consider the total height of the vehicle and load, including roof-mounted equipment, machinery, cargo or other items that increase the overall vehicle height.

Why Is the W320 Height Restriction Sign Important?

A high vehicle approaching a low-clearance structure may not have enough space to pass safely through the restriction.

Advance warning gives affected drivers information before they reach the restricted location, allowing them to check their vehicle height and follow an appropriate alternative route where necessary.

W320 is therefore especially relevant to commercial vehicle operators and transport businesses whose vehicles may have greater overall heights.

W320 and the 4.7 m Clearance Requirement

The SARTSM specifies W320 when the clearance over any part of the roadway is below 4.7 m.

The clearance should be assessed over the complete usable roadway area, since the available height may vary across different portions of the road.

The displayed restriction should accurately reflect the actual applicable clearance at the site.

W320 and the R204 Height Limit Sign

W320 is the advance warning sign, while R204 Height Limit is the regulatory sign at the actual restriction.

The height shown on W320 must be the same as the height shown on R204.

This provides consistency between the advance warning and the restriction at the structure.

W320 and W415 Overhead Danger Plates

At the overhead structure, the R204 Height Limit sign is displayed on the structure and is flanked by two W415 Overhead Danger Plates.

This forms part of the complete height-restriction signing arrangement at the restricted location.

W320 at Railway Crossings

W320 has a specific application at a railway crossing where a height gauge is located ahead and overhead electrical power cables are installed above the railway crossing.

The height gauge provides a physical indication of the available clearance, while W320 gives drivers advance warning of the restricted height.

Where the overhead electrical cable clearance is subject to the relevant height restriction, the R204 Height Limit sign and required hazard markers must also be provided at the height gauge.

W320 at Overhead Structures

W320 can also be used in advance of an overhead structure where the available clearance is restricted.

Examples can include:

• Low bridges
• Overhead road structures
• Low-clearance structures
• Other structures crossing above the roadway

The actual sign arrangement should reflect the physical restriction and the applicable South African road traffic sign requirements.

W320 Sign Placement

W320 should be positioned in advance of the height restriction.

The SARTSM states that the sign should be located according to the design speed of the road and should be of the size indicated in Table 3.1.

The exact distance therefore depends on the characteristics and operating conditions of the road.

W320 and Distance Information Plates

W320 may be positioned some distance away from the actual height restriction.

When the warning sign is located some distance from the hazard, it should be supplemented with a distance information plate indicating the distance to the restriction.

This gives drivers additional information about how far they have to travel before reaching the low-clearance point.

How Should Drivers Respond to W320?

Drivers approaching W320 should become aware that a height restriction is ahead.

Drivers of high vehicles should:

• Check the vehicle's total height.
• Check the height of the load or equipment carried.
• Read the height shown on the warning sign.
• Look for the R204 Height Limit sign at the restriction.
• Follow any alternative-route instructions provided.
• Do not proceed through the restriction when the vehicle exceeds the applicable height limit.

Drivers should not rely on visual estimates of clearance when an official height limit is displayed.

W320 Does Not Set the Height Limit by Itself

W320 is an advance warning sign.

The actual restriction is controlled by the applicable R204 Height Limit sign at the restricted location.

The height displayed on W320 should match the height displayed on R204.

Vehicles That Should Pay Particular Attention to W320

Height restrictions can be especially important for:

• Heavy trucks
• Delivery trucks
• Buses and coaches
• Trailers
• Articulated vehicles
• Caravans
• Vehicle transporters
• Specialised transport vehicles
• Vehicles carrying tall equipment
• Vehicles carrying oversized or high loads

Passenger cars that are well below the displayed clearance are normally less affected, but all drivers should remain aware of the restriction and applicable traffic controls.

W320 and Tall Loads

A vehicle's height must include everything being carried or mounted on the vehicle.

A truck that normally has sufficient clearance may exceed the restriction after carrying tall cargo, machinery, containers or other equipment.

Transport operators should therefore verify the full vehicle-and-load height before selecting routes with known height restrictions.

W320 and Route Planning

High-vehicle operators should consider height restrictions during route planning rather than reaching the restriction before discovering that the vehicle cannot pass.

Route planning for tall vehicles can include checking:

• Vehicle height
• Load height
• Bridge clearances
• Railway crossing restrictions
• Overhead structures
• Alternative routes

Where the vehicle exceeds the permitted height, an appropriate alternative route should be selected.

W320 and Low Bridges

Low bridges can create a height restriction where the available clearance is below the applicable threshold.

W320 gives approaching drivers advance warning before they reach the structure.

The actual permitted height should be clearly displayed at the restriction using the applicable R204 Height Limit sign.

W320 at Railway Overhead Power Cables

Railway crossings with overhead electrical power cables can require a height gauge to warn drivers about the clearance and the risks associated with high vehicles or raised objects.

The SARTSM provides specific requirements for height gauges and warning arrangements at these railway crossings.

Where the clearance is below 4.7 m, an appropriate R204 Height Limit sign and hazard-marker arrangement are required at the height gauge, with W320 providing advance warning.

W320 and Overhead Electrical Hazards

A height restriction at a railway crossing with overhead electrical equipment is not only about vehicle clearance.

High aerials, raised equipment or other elevated objects can present a risk around overhead electrical power cables. The crossing's warning and control arrangement should therefore be followed carefully.

W320 During Roadworks

Construction and maintenance work can temporarily reduce the normal clearance beneath an overhead structure.

Where this happens, a temporary height-restriction warning may be required so that drivers are aware of the changed clearance before reaching the affected location.

Temporary Height Restriction Sign – TW320

The temporary version of W320 is designated TW320.

The SARTSM states that TW320 may be used under the same circumstances as the permanent W320 where construction or maintenance work temporarily reduces the normal height restriction at a structure.

TW320 should form part of the applicable temporary traffic-management arrangement for the work site.

Permanent W320 Sign Design and Colours

The permanent W320 warning sign uses:

• Triangle: Red retroreflective
• Symbol: Black semi-matt
• Background: White retroreflective
• Legend: DIN 1451 Style B

The numerical clearance displayed on the sign communicates the applicable height restriction ahead.

Temporary TW320 Sign Design and Colours

The temporary TW320 warning sign uses:

• Triangle: Red retroreflective
• Symbol: Black semi-matt
• Background: Yellow retroreflective
• Legend: DIN 1451 Style B

The yellow background identifies the warning as temporary.

Retroreflective W320 Signs

Retroreflective materials help warning signs remain visible when illuminated by vehicle headlights, especially during lower-light conditions.

For public-road applications, W320 signs should be manufactured with the correct dimensions, materials, colours, symbols and lettering specified by the applicable South African road traffic sign requirements.

W320 Sign Visibility

The warning should be visible far enough in advance for affected drivers to understand the restriction and make an appropriate decision.

Visibility can be affected by:

• Road curves
• Hills and crests
• Vegetation
• Buildings and structures
• Advertising boards
• Other roadside signs
• Poor lighting
• Heavy traffic

The sign should be positioned and maintained so that approaching drivers can clearly identify it.

W320 Sign Size

The appropriate size of W320 depends on the road environment and applicable warning-sign requirements.

The SARTSM specifies that W320 should be of the size indicated in Table 3.1. Sign-size selection for a particular installation should also reflect the road's design and operating conditions.

W320 Sign Maintenance

Height-restriction signs should remain clear, legible and visible.

Maintenance checks should identify issues such as:

• Faded sign faces
• Damaged numerals
• Physical damage
• Loose mounting hardware
• Vegetation covering the sign
• Other obstructions
• Reduced retroreflective performance

The displayed height should also remain consistent between the W320 advance warning and the R204 restriction at the hazard.

W320 and Changing Clearance

Clearance can change temporarily because of construction, maintenance, temporary structures or changes to a roadway.

Where work reduces the normal clearance, the temporary traffic-management arrangement should clearly communicate the new restriction.

TW320 may be used where the circumstances meet the SARTSM requirements for a temporary reduction in height clearance.

W320 on Public Roads in South Africa

The W320 Height Restricted sign forms part of the South African road traffic warning-sign system.

For public-road use, the selection, design, height value, dimensions, placement, materials and installation of W320 should comply with the applicable South African Road Traffic Signs Manual requirements and the requirements of the responsible road authority.

The associated R204 Height Limit sign should display the corresponding applicable restriction at the hazard.

W320 on Private Roads and Properties

Height restrictions can also occur on private roads and controlled properties.

Similar height-restriction warning signage may be used at:

• Warehouses
• Distribution centres
• Industrial properties
• Parking facilities
• Shopping centres
• Residential developments
• Farms
• Private bridges
• Construction sites
• Loading and service areas

On private property, the signage can form part of an internal traffic-management system based on the actual clearance restrictions at the site.

W320 at Parking Facilities

Parking garages, covered loading areas and building entrances may have limited clearance that affects trucks, vans, buses and other taller vehicles.

Where vehicle clearance is restricted on private property, the maximum permitted height should be displayed clearly and accurately so that drivers can assess whether their vehicles can enter.

W320 and Commercial Transport

Commercial transport operators should keep accurate information about the overall height of their vehicles and loads.

This is especially important for delivery vehicles, freight trucks, trailers and specialised transport where equipment or cargo can significantly increase total height.

W320 and Oversized Loads

Vehicles carrying unusually tall or oversized loads may need additional route planning.

Operators should verify route suitability and comply with any applicable requirements before travelling through roads containing height-restricted structures.

Who May Need W320 Height Restriction Signs?

W320 signage may be relevant to:

• Road authorities
• Municipalities
• Railway infrastructure operators
• Road construction contractors
• Bridge and infrastructure operators
• Mining operations
• Industrial facilities
• Warehouses
• Distribution centres
• Parking facility operators
• Property developers
• Transport and logistics companies
• Traffic-management contractors
• Private facility managers

Benefits of Height Restriction Warning Signs

• Warns drivers that vertical clearance is restricted ahead.
• Provides advance information before a low-clearance structure.
• Helps high-vehicle drivers identify a possible route restriction.
• Can be used at overhead structures and railway height gauges.
• Helps drivers compare the restriction with the vehicle and load height.
• Can form part of a complete W320, R204 and W415 signing arrangement.
• Can include a distance information plate where the warning is positioned away from the hazard.
• TW320 can provide temporary warning when construction or maintenance reduces normal clearance.

Frequently Asked Questions About W320 Road Signs

What does W320 mean?

W320 means Height Restricted. It warns road users that vertical clearance ahead is restricted.

What is W320 used for?

W320 warns about restricted clearance at an overhead structure or a height gauge associated with a railway crossing.

How low must the clearance be for W320?

The SARTSM specifies W320 where the clearance over any portion of the roadway is less than 4.7 m.

What is the difference between W320 and R204?

W320 gives advance warning, while R204 Height Limit gives the applicable restriction at the hazard.

What height should be shown on W320?

The height shown on W320 should be the same as the height shown on the associated R204 Height Limit sign.

What is W415?

W415 Overhead Danger Plates are displayed with the R204 Height Limit arrangement at the restricted overhead structure.

Can W320 be used at a low bridge?

Yes. W320 can warn of restricted vertical clearance at an overhead structure such as a low bridge.

Can W320 be used at a railway crossing?

Yes. It can warn of a height gauge at a railway crossing with overhead electrical power cables.

Does W320 itself create the height restriction?

No. W320 is the advance warning. The applicable regulatory height restriction is displayed by R204 at the restricted location.

Does W320 mean I must stop?

No. W320 itself is an advance warning. Drivers must follow the actual restriction and any applicable traffic controls at the hazard.

Does W320 set a speed limit?

No. W320 concerns vehicle height clearance, not speed.

Which vehicles should pay particular attention to W320?

High trucks, buses, trailers, caravans, specialised vehicles and vehicles carrying tall loads should pay particular attention.

Should I include the load when checking vehicle height?

Yes. The total height should include the vehicle, cargo, equipment and anything else extending above the vehicle.

What should I do if my vehicle is taller than the displayed limit?

Do not proceed through the restriction. Follow an appropriate alternative route or other applicable instructions.

Can W320 be supplemented with a distance plate?

Yes. When W320 is positioned some distance from the hazard, it should be supplemented with a distance information plate showing the distance to the restriction.

What is TW320?

TW320 is the temporary Height Restricted warning sign.

When is TW320 used?

TW320 may be used when construction or maintenance temporarily reduces the normal height restriction at a structure.

What colours does a permanent W320 sign use?

The permanent sign uses a red retroreflective triangle, black semi-matt symbol and white retroreflective background.

What colours does TW320 use?

The temporary version uses a red retroreflective triangle, black semi-matt symbol and yellow retroreflective background.

What is the purpose of a height gauge at a railway crossing?

A height gauge provides a physical clearance reference where overhead electrical power cables are present above the crossing.

Can W320 be used on private property?

Similar height-restriction warning signs may be used on private roads and controlled properties where vehicle clearance is limited.

Can W320 be used at a parking garage?

Similar height-clearance signage can be used at private parking facilities where vehicle access is limited by a low structure.

Can Signs4SA supply W320 signs?

Yes. Signs4SA can assist with W320 Height Restricted warning signs, R204 Height Limit signs, W415 Overhead Danger Plates and other traffic-management signage.

Order W320 Height Restriction Ahead Road Signs

Need W320 Height Restriction Ahead signs for a low bridge, railway crossing, industrial site, warehouse, parking facility, road project or traffic-management application?

Contact Signs4SA with your required sign code, clearance height, dimensions, quantity and installation details to request a quotation.

One important feature of Height restriction ahead signs is their high visibility. These signs are designed to be easily seen by drivers, even from a distance and in adverse weather conditions. Many Height restriction ahead signs are also designed with reflective materials that make them visible at night.

Another important feature of Height restriction ahead signs is their durability. Road signs are exposed to a wide range of environmental factors, including wind, rain, and extreme temperatures. As such, they need to be made from materials that can withstand these conditions and remain in good condition for years to come.

More About Height restriction ahead

Height Restriction Ahead – W320 Road Sign

The W320 Height Restriction Ahead road sign is a warning sign used to alert drivers that the available vertical clearance above the roadway is restricted ahead.

The official South African designation is HEIGHT RESTRICTED. W320 is used where a height gauge associated with a railway crossing or an overhead structure creates a restricted clearance for vehicles.

The sign is particularly important for trucks, buses, trailers, caravans, delivery vehicles and other high vehicles that may exceed the available clearance.

What Does the W320 Road Sign Mean?

W320 means Height Restricted. It warns road users that the vertical clearance ahead is limited.

The restriction may relate to:

• A height gauge at a railway crossing with overhead electrical power cables
• An overhead bridge or other structure
• Another overhead obstruction where the available clearance is restricted

W320 provides advance warning. The actual height limit at the restriction is shown by the applicable R204 Height Limit regulatory sign.

When Is W320 Used?

The South African Road Traffic Signs Manual states that W320 should be displayed in advance of a height gauge or overhead structure when the clearance over any portion of the roadway is less than 4.7 m.

This means W320 is not simply a general warning for every bridge or overhead structure. It is specifically associated with restricted vertical clearance.

What Does Vertical Clearance Mean?

Vertical clearance is the available height between the highest point of the roadway and the lowest point of the overhead obstruction.

For a vehicle to pass through the restriction, the vehicle and its load must remain within the available clearance.

Drivers should consider the total height of the vehicle and load, including roof-mounted equipment, machinery, cargo or other items that increase the overall vehicle height.

Why Is the W320 Height Restriction Sign Important?

A high vehicle approaching a low-clearance structure may not have enough space to pass safely through the restriction.

Advance warning gives affected drivers information before they reach the restricted location, allowing them to check their vehicle height and follow an appropriate alternative route where necessary.

W320 is therefore especially relevant to commercial vehicle operators and transport businesses whose vehicles may have greater overall heights.

W320 and the 4.7 m Clearance Requirement

The SARTSM specifies W320 when the clearance over any part of the roadway is below 4.7 m.

The clearance should be assessed over the complete usable roadway area, since the available height may vary across different portions of the road.

The displayed restriction should accurately reflect the actual applicable clearance at the site.

W320 and the R204 Height Limit Sign

W320 is the advance warning sign, while R204 Height Limit is the regulatory sign at the actual restriction.

The height shown on W320 must be the same as the height shown on R204.

This provides consistency between the advance warning and the restriction at the structure.

W320 and W415 Overhead Danger Plates

At the overhead structure, the R204 Height Limit sign is displayed on the structure and is flanked by two W415 Overhead Danger Plates.

This forms part of the complete height-restriction signing arrangement at the restricted location.

W320 at Railway Crossings

W320 has a specific application at a railway crossing where a height gauge is located ahead and overhead electrical power cables are installed above the railway crossing.

The height gauge provides a physical indication of the available clearance, while W320 gives drivers advance warning of the restricted height.

Where the overhead electrical cable clearance is subject to the relevant height restriction, the R204 Height Limit sign and required hazard markers must also be provided at the height gauge.

W320 at Overhead Structures

W320 can also be used in advance of an overhead structure where the available clearance is restricted.

Examples can include:

• Low bridges
• Overhead road structures
• Low-clearance structures
• Other structures crossing above the roadway

The actual sign arrangement should reflect the physical restriction and the applicable South African road traffic sign requirements.

W320 Sign Placement

W320 should be positioned in advance of the height restriction.

The SARTSM states that the sign should be located according to the design speed of the road and should be of the size indicated in Table 3.1.

The exact distance therefore depends on the characteristics and operating conditions of the road.

W320 and Distance Information Plates

W320 may be positioned some distance away from the actual height restriction.

When the warning sign is located some distance from the hazard, it should be supplemented with a distance information plate indicating the distance to the restriction.

This gives drivers additional information about how far they have to travel before reaching the low-clearance point.

How Should Drivers Respond to W320?

Drivers approaching W320 should become aware that a height restriction is ahead.

Drivers of high vehicles should:

• Check the vehicle's total height.
• Check the height of the load or equipment carried.
• Read the height shown on the warning sign.
• Look for the R204 Height Limit sign at the restriction.
• Follow any alternative-route instructions provided.
• Do not proceed through the restriction when the vehicle exceeds the applicable height limit.

Drivers should not rely on visual estimates of clearance when an official height limit is displayed.

W320 Does Not Set the Height Limit by Itself

W320 is an advance warning sign.

The actual restriction is controlled by the applicable R204 Height Limit sign at the restricted location.

The height displayed on W320 should match the height displayed on R204.

Vehicles That Should Pay Particular Attention to W320

Height restrictions can be especially important for:

• Heavy trucks
• Delivery trucks
• Buses and coaches
• Trailers
• Articulated vehicles
• Caravans
• Vehicle transporters
• Specialised transport vehicles
• Vehicles carrying tall equipment
• Vehicles carrying oversized or high loads

Passenger cars that are well below the displayed clearance are normally less affected, but all drivers should remain aware of the restriction and applicable traffic controls.

W320 and Tall Loads

A vehicle's height must include everything being carried or mounted on the vehicle.

A truck that normally has sufficient clearance may exceed the restriction after carrying tall cargo, machinery, containers or other equipment.

Transport operators should therefore verify the full vehicle-and-load height before selecting routes with known height restrictions.

W320 and Route Planning

High-vehicle operators should consider height restrictions during route planning rather than reaching the restriction before discovering that the vehicle cannot pass.

Route planning for tall vehicles can include checking:

• Vehicle height
• Load height
• Bridge clearances
• Railway crossing restrictions
• Overhead structures
• Alternative routes

Where the vehicle exceeds the permitted height, an appropriate alternative route should be selected.

W320 and Low Bridges

Low bridges can create a height restriction where the available clearance is below the applicable threshold.

W320 gives approaching drivers advance warning before they reach the structure.

The actual permitted height should be clearly displayed at the restriction using the applicable R204 Height Limit sign.

W320 at Railway Overhead Power Cables

Railway crossings with overhead electrical power cables can require a height gauge to warn drivers about the clearance and the risks associated with high vehicles or raised objects.

The SARTSM provides specific requirements for height gauges and warning arrangements at these railway crossings.

Where the clearance is below 4.7 m, an appropriate R204 Height Limit sign and hazard-marker arrangement are required at the height gauge, with W320 providing advance warning.

W320 and Overhead Electrical Hazards

A height restriction at a railway crossing with overhead electrical equipment is not only about vehicle clearance.

High aerials, raised equipment or other elevated objects can present a risk around overhead electrical power cables. The crossing's warning and control arrangement should therefore be followed carefully.

W320 During Roadworks

Construction and maintenance work can temporarily reduce the normal clearance beneath an overhead structure.

Where this happens, a temporary height-restriction warning may be required so that drivers are aware of the changed clearance before reaching the affected location.

Temporary Height Restriction Sign – TW320

The temporary version of W320 is designated TW320.

The SARTSM states that TW320 may be used under the same circumstances as the permanent W320 where construction or maintenance work temporarily reduces the normal height restriction at a structure.

TW320 should form part of the applicable temporary traffic-management arrangement for the work site.

Permanent W320 Sign Design and Colours

The permanent W320 warning sign uses:

• Triangle: Red retroreflective
• Symbol: Black semi-matt
• Background: White retroreflective
• Legend: DIN 1451 Style B

The numerical clearance displayed on the sign communicates the applicable height restriction ahead.

Temporary TW320 Sign Design and Colours

The temporary TW320 warning sign uses:

• Triangle: Red retroreflective
• Symbol: Black semi-matt
• Background: Yellow retroreflective
• Legend: DIN 1451 Style B

The yellow background identifies the warning as temporary.

Retroreflective W320 Signs

Retroreflective materials help warning signs remain visible when illuminated by vehicle headlights, especially during lower-light conditions.

For public-road applications, W320 signs should be manufactured with the correct dimensions, materials, colours, symbols and lettering specified by the applicable South African road traffic sign requirements.

W320 Sign Visibility

The warning should be visible far enough in advance for affected drivers to understand the restriction and make an appropriate decision.

Visibility can be affected by:

• Road curves
• Hills and crests
• Vegetation
• Buildings and structures
• Advertising boards
• Other roadside signs
• Poor lighting
• Heavy traffic

The sign should be positioned and maintained so that approaching drivers can clearly identify it.

W320 Sign Size

The appropriate size of W320 depends on the road environment and applicable warning-sign requirements.

The SARTSM specifies that W320 should be of the size indicated in Table 3.1. Sign-size selection for a particular installation should also reflect the road's design and operating conditions.

W320 Sign Maintenance

Height-restriction signs should remain clear, legible and visible.

Maintenance checks should identify issues such as:

• Faded sign faces
• Damaged numerals
• Physical damage
• Loose mounting hardware
• Vegetation covering the sign
• Other obstructions
• Reduced retroreflective performance

The displayed height should also remain consistent between the W320 advance warning and the R204 restriction at the hazard.

W320 and Changing Clearance

Clearance can change temporarily because of construction, maintenance, temporary structures or changes to a roadway.

Where work reduces the normal clearance, the temporary traffic-management arrangement should clearly communicate the new restriction.

TW320 may be used where the circumstances meet the SARTSM requirements for a temporary reduction in height clearance.

W320 on Public Roads in South Africa

The W320 Height Restricted sign forms part of the South African road traffic warning-sign system.

For public-road use, the selection, design, height value, dimensions, placement, materials and installation of W320 should comply with the applicable South African Road Traffic Signs Manual requirements and the requirements of the responsible road authority.

The associated R204 Height Limit sign should display the corresponding applicable restriction at the hazard.

W320 on Private Roads and Properties

Height restrictions can also occur on private roads and controlled properties.

Similar height-restriction warning signage may be used at:

• Warehouses
• Distribution centres
• Industrial properties
• Parking facilities
• Shopping centres
• Residential developments
• Farms
• Private bridges
• Construction sites
• Loading and service areas

On private property, the signage can form part of an internal traffic-management system based on the actual clearance restrictions at the site.

W320 at Parking Facilities

Parking garages, covered loading areas and building entrances may have limited clearance that affects trucks, vans, buses and other taller vehicles.

Where vehicle clearance is restricted on private property, the maximum permitted height should be displayed clearly and accurately so that drivers can assess whether their vehicles can enter.

W320 and Commercial Transport

Commercial transport operators should keep accurate information about the overall height of their vehicles and loads.

This is especially important for delivery vehicles, freight trucks, trailers and specialised transport where equipment or cargo can significantly increase total height.

W320 and Oversized Loads

Vehicles carrying unusually tall or oversized loads may need additional route planning.

Operators should verify route suitability and comply with any applicable requirements before travelling through roads containing height-restricted structures.

Who May Need W320 Height Restriction Signs?

W320 signage may be relevant to:

• Road authorities
• Municipalities
• Railway infrastructure operators
• Road construction contractors
• Bridge and infrastructure operators
• Mining operations
• Industrial facilities
• Warehouses
• Distribution centres
• Parking facility operators
• Property developers
• Transport and logistics companies
• Traffic-management contractors
• Private facility managers

Benefits of Height Restriction Warning Signs

• Warns drivers that vertical clearance is restricted ahead.
• Provides advance information before a low-clearance structure.
• Helps high-vehicle drivers identify a possible route restriction.
• Can be used at overhead structures and railway height gauges.
• Helps drivers compare the restriction with the vehicle and load height.
• Can form part of a complete W320, R204 and W415 signing arrangement.
• Can include a distance information plate where the warning is positioned away from the hazard.
• TW320 can provide temporary warning when construction or maintenance reduces normal clearance.

Frequently Asked Questions About W320 Road Signs

What does W320 mean?

W320 means Height Restricted. It warns road users that vertical clearance ahead is restricted.

What is W320 used for?

W320 warns about restricted clearance at an overhead structure or a height gauge associated with a railway crossing.

How low must the clearance be for W320?

The SARTSM specifies W320 where the clearance over any portion of the roadway is less than 4.7 m.

What is the difference between W320 and R204?

W320 gives advance warning, while R204 Height Limit gives the applicable restriction at the hazard.

What height should be shown on W320?

The height shown on W320 should be the same as the height shown on the associated R204 Height Limit sign.

What is W415?

W415 Overhead Danger Plates are displayed with the R204 Height Limit arrangement at the restricted overhead structure.

Can W320 be used at a low bridge?

Yes. W320 can warn of restricted vertical clearance at an overhead structure such as a low bridge.

Can W320 be used at a railway crossing?

Yes. It can warn of a height gauge at a railway crossing with overhead electrical power cables.

Does W320 itself create the height restriction?

No. W320 is the advance warning. The applicable regulatory height restriction is displayed by R204 at the restricted location.

Does W320 mean I must stop?

No. W320 itself is an advance warning. Drivers must follow the actual restriction and any applicable traffic controls at the hazard.

Does W320 set a speed limit?

No. W320 concerns vehicle height clearance, not speed.

Which vehicles should pay particular attention to W320?

High trucks, buses, trailers, caravans, specialised vehicles and vehicles carrying tall loads should pay particular attention.

Should I include the load when checking vehicle height?

Yes. The total height should include the vehicle, cargo, equipment and anything else extending above the vehicle.

What should I do if my vehicle is taller than the displayed limit?

Do not proceed through the restriction. Follow an appropriate alternative route or other applicable instructions.

Can W320 be supplemented with a distance plate?

Yes. When W320 is positioned some distance from the hazard, it should be supplemented with a distance information plate showing the distance to the restriction.

What is TW320?

TW320 is the temporary Height Restricted warning sign.

When is TW320 used?

TW320 may be used when construction or maintenance temporarily reduces the normal height restriction at a structure.

What colours does a permanent W320 sign use?

The permanent sign uses a red retroreflective triangle, black semi-matt symbol and white retroreflective background.

What colours does TW320 use?

The temporary version uses a red retroreflective triangle, black semi-matt symbol and yellow retroreflective background.

What is the purpose of a height gauge at a railway crossing?

A height gauge provides a physical clearance reference where overhead electrical power cables are present above the crossing.

Can W320 be used on private property?

Similar height-restriction warning signs may be used on private roads and controlled properties where vehicle clearance is limited.

Can W320 be used at a parking garage?

Similar height-clearance signage can be used at private parking facilities where vehicle access is limited by a low structure.

Can Signs4SA supply W320 signs?

Yes. Signs4SA can assist with W320 Height Restricted warning signs, R204 Height Limit signs, W415 Overhead Danger Plates and other traffic-management signage.

Order W320 Height Restriction Ahead Road Signs

Need W320 Height Restriction Ahead signs for a low bridge, railway crossing, industrial site, warehouse, parking facility, road project or traffic-management application?

Contact Signs4SA with your required sign code, clearance height, dimensions, quantity and installation details to request a quotation.

One popular type of road sign is the Height restriction ahead sign. This type of sign is used to provide drivers with important information about the road ahead, such as directions, speed limits, and potential hazards.

Height restriction ahead_ signs come in a variety of shapes and sizes, and are made from a range of materials, including metal, plastic, and reflective materials. They can be customized to meet the specific needs of a particular roadway or location, including the addition of logos, graphics, and text.

One important feature of Height restriction ahead signs is their high visibility. These signs are designed to be easily seen by drivers, even from a distance and in adverse weather conditions. Many Height restriction ahead signs are also designed with reflective materials that make them visible at night.

Another important feature of Height restriction ahead signs is their durability. Road signs are exposed to a wide range of environmental factors, including wind, rain, and extreme temperatures. As such, they need to be made from materials that can withstand these conditions and remain in good condition for years to come.

For businesses and organizations that need to create custom road signs, working with a reputable sign company can ensure that their signs are of high quality and meet all necessary standards and regulations. Signs4sa can provide expert advice on design, materials, and installation, and can help businesses ensure that their signs are installed safely and effectively.

Overall, Height restriction ahead signs are an important tool for ensuring road safety and providing drivers with the information they need to navigate effectively. By working with a professional sign company to create and install these signs, businesses and organizations can help ensure that their messages are seen and understood by drivers, and help to improve safety on the road.

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