LSM BridgeSense® (int.pat.pend) Vehicle Over- Height / Dimensioned (CAAS) Collision Avoidance / Awareness System

LSM BridgeSense® Vehicle Over- Height / Dimensioned (CAAS) Collision Avoidance / Awareness System

LSM BridgeSense® (int.pat.pend) is designed to eliminate / avoid Over - Height Vehicles / Loads impacting / striking on Bridges / Tunnels (Overhead structures), as well as providing Over- Bridge protection from vehicles Over- Weight / Dimensioned.

LSM BridgeSense® Vehicle Over- Height / Dimensioned (CAAS) Collision Avoidance / Awareness System
Overview / Over- Height InteractionsOVERVIEW / OVER- HEIGHT INTERACTIONS
Current Mitigation Controls + IssuesCURRENT MITIGATION CONTROLS + ISSUES
Bridge Sense® How It WorksBRIDGE SENSE® HOW IT WORKS
Development / Implementation / CostDEVELOPMENT / IMPLEMENTATION / COST
More Info / Products / VideosMORE INFO / PRODUCTS / VIDEOS
Overview / Over- Height Interactions

Vehicle collisions with overhead structures, such as Overpasses, Bridges and Tunnels (and Sacrificial Structures), are a common occurrence worldwide that cause significant damage to critical infrastructure and delays along busy traffic routes. Such impacts cost many hundreds of $$million's in damaged infrastructure, vehicles / loads, traffic delays, emergency responses, injury / fatality and more.

Bridge / Overhead Structure Impact incidents are continuing to occur globally. 

Overhead structure Impacts are virtually an everyday event worldwide, involving Vehicles (Buses, Trucks, Cement Agitators-even Caravans) as well as Over - Height Loads on TrailersTipper Bins, Truck Cranes, etc and there does not seem to be a solution to abate the situation.

A few statistics for Australia and Internationally are:

  • 2022: In Australia, there are around 53,000 public road bridges. 
  • 2021: Queensland Rail (QR) confirmed that in the last three years, 253 bridge strikes had caused over a 1,000 service delays
  • 2021- 2022: In the last financial year, 65 bridge strikes were across the Queensland Rail network and also 279 collisions were with Protection Beams.
  • 2021: In the past 5 years, QR has invested $15.5 million to install Bridge Protection Beams on the approach to 14 high-priority Bridges across South East Queensland to prevent Over - height vehicles from colliding with bridges and to minimise train delays
  • 2021: Office of the National Rail Safety Regulator (ONRSR)  reminded rail transport operators about a range of risks, causes and controls associated with road vehicles or vessels striking rail bridges. These incidents can result in derailments and collisions that can ultimately cause serious injuries and even fatalities
  • 2021: Network Rail- UK advised that there were 1,624 bridge strikes reported across the network. Railway Bridge impacts cost of around GBP13,000 per strike- costing the UK taxpayer around GBP23 million in a year. 
  • 2021: National Highway Traffic Safety Administration (NHTSA) report that in the USA Bridges are impacted (struck and damaged) on average 15,000 times a year- as of 2022 the USA has 614,387 Bridges. 
Bridge Impact 003 x 800x500.png
Bridge Impact 004 x 800x500.png

LSM Technologies posts some reported Vehicle Over - Height collisions that have taken place around the World on our LinkedIn page- see this link for more details.

Current Mitigation Controls + Issues

Current Impact Mitigation Controls

Currently, our research has disclosed that the primary types of mitigation technologies utilised for CAS for Over- Height Vehicle Detection System (OVDS) for predetermining a collision between a vehicle and an overhead structure are:

  • Laser and Ultrasonic Sensors: These are placed upon a structure / frame straddled over the road and positioned before the approach of a bridge / structure. If an Over- Height vehicle is detected (sensors or by breaching the laser beam) then warning lights / signs provide the Driver with an alert. Some systems also will initiate an On - board warning device (if fitted) in the vehicle to alert the Driver. 
  • Approach Protection Beam (Sacrificial) Structure: This is a solid structure / frame positioned over the road as a “sacrificial” structure where an over height vehicle will impact / damage the frame and vehicle rather than the proceeding Bridge / Structure. 
  • Rumble Strips / Curtains: These are tubular structures that hang from a pole / frame structures that are placed over the road before the approach of the Bridge / Structure. If the vehicle / load is Over- Height then these are contacted and make subsequent noise with the objective of notifying the Driver that they are Over - Height.
  • Other: A few other types of mitigation controls are utilised (such as flashing lights, warning signs, holographic images, etc).

All these technologies can be combined to provide visual (audible) alerts in an endeavour to make the Driver aware of Bridge Heights / avoid striking, on vehicle approach.  

Issues with these mitigation controls are:

  • Enormous expense to implement, repair and maintain. 
  • Effects upon other traffic with falling debris - impact / clean - up (e.g. sacrificial structure / rumble curtains) and could damage other vehicles or harm other road users.  
  • Use of Rumble Curtains may not be heard or felt by the Driver and if they are, by the time the Driver is aware, it is generally too late
  • Warning accuracy at the range of vehicle speeds to provide over - height warning may not be quick enough for the driver (laser / sensors) to avoid impact. 
  • Overall functionality, accuracy (laser / sensors) with errors and false positives caused by environmental conditions such as weather (snow, hail, rain, etc.), traffic (parallel vehicles driving and excess speed). 
  • Other issues such as birds crossing and dust infiltration onto / into laser / sensors
  • Multiple vehicles driving side by side in a multi-lane road can yield false alarms if one of the vehicles does not exceed height limitations (laser / sensors)
  • Complex setups and access for workers to provide maintenance, especially in busy intersections and highways. 
  • Warning signs, flashing lights, etc blend into the Driver's operating environment, are usually placed close to the Bridge / Structure and at speed, driver awareness is made too late. 
  • Other aspects are error correction, false positives, power requirements, costs.

Other Impact Mitigation Controls

Other technologies have been available for some years, such as Google Maps type routing applications like Truckwiz and Route Planners like TMR's Condition of Operations Database (QLD) and the NHVR Route Planner Database (National Planner). 

However, this type of Satellite Navigational  / App (Sat Nav) technology also does not seem to be effective, as Vehicles and Loads are still hitting Bridges

In analysis, some perceived issues with these technologies could be: 

  • Accuracy with general Sat Nav and iPhones / PDA type Apps. 
  • Not everyone has a Sat Nav System installed in their vehicle and if so, it is not necessarily turned - on or in use when the vehicle is travelling.  
  • If the Driver is using an App (iPhone / PDA) they have to remember to add the App to one's iPhone and have the iPhone / App active at all times within the Driver's peripheral / access to hear / see alerts.  
  • Not everyone has an iPhone / PDA device or is allowed to have it active within a vehicle or using whilst driving. . 
  • Apps relying on GSM / Mobile data network and coverage can be limited and accuracy / drop- outs in remote areas are quite frequent. 
  • Drivers are busy doing other things such as loading, completing paperwork, travel log, etc and subsequently can forget to add changes or make a route in an App or Sat Nav Device.
  • iPhone / PDA Apps cost $$ and usually have an annual subscription and require a GSM data plan charge. 
  • A Driver still needs to take the time to add a route and update if required, whilst they are in transit, if the route changes

Error / Distraction / Complacency / Situation Awareness

Human Error and other causations are contributing factors as to why the above types of mitigation controls are not affective solutions:  

  • Wherever there is a need for "human" interaction, then there is a significant potential for an incident due to delay in responding / taking action.
  • Human Error (see link to NRSPP) and Distraction (see link to NRSPP) are perceived as big issues.
  • Complacency is a contributing factor, where a Driver can become "blinded" (does not "see") warning signs or even flashing lights and even boom gates.  
  • Situation Awareness > Decision > Acton - Response (see this link) takes time to implement corrective action. It is known that a driver can take between 1.5- 2.5 seconds (or longer with fatigue) to become Aware there is a need to take action. Thinking time is required to make a Decision for corrective Action (eg start to apply brakes). For a Truck and single Trailer, it takes about 4.6 seconds to bring the Rig to a stop - longer for larger Rigs.
  • At 100 km / hour in- dry conditions, stopping distance can be >200 metres, With longer Rigs, wet conditions, braking distance can again take a lot longer.

Utilising a fully autonomous technology of LSM BridgeSense® provides the Driver with a pre-warning of the potential impact on Bridges / Other Road Structures and can initiate deceleration or even AEB (Automatic Emergency Braking) if required.

Bridge Impact 006 x 800x500.png
Bridge Impact Protect 001 800x500.png
Impact Structure 02 800x500.png
Bridge Sign 007 800x500.png
Bridge Sign 003 800x500.png

As described in our LSM TrainSense® Railway Level Crossings's CAAS mitigation control Google Maps Apps, In- vehicle Navigational devices and Online Route Planning systems are available for depicting Railway Level Crossing's. Please see our LSM TrainSense® section to read why these systems are believed to be unreliable and ineffective as mitigation controls.

Heavy Penalties

Other significant countermeasures by Regulators have been to apply heavy $$ penalties, removal of offending Trucks / Drivers from operating and even threatening incarceration of Transport Operators / Driver for such impacts.

However, whilst such penalties make act as some determent, they are not a "proactive" mitigation control, and are applied "after- the fact" of a possible catastrophic event, severe costs damage / repairs / disruptioninjury / fatality and really will not be a permanent "fix" to stopping Vehicles impacting Bridges and other Structures around the world.

LSM BridgeSense® How- It- Works

The design concept for LSM BridgeSense® Over - Height CAS Technology is to provide a simple yet effective and autonomous mitigation control.

Not only can it provide for Driver Alerts when approaching Bridges / Tunnels  / Structures for Vehicle Over - Height, but also for Over- Dimensioned as well as Over-Weight -when travelling Over Bridges.

To the right is a schematic of our LSM BridgeSense® mitigation technology, with the following overview / functionality of the Device concept:      

Over- Height Mitigaiton.

  • The concept is a small “Tag” (like a Toll Tag) Device that is permanently affixed inside the Cabin of the Vehicle, located behind the Cabin Rearview Mirror.
  • The Device contains a stored Database of all Mapped Bridge / Tunnel / Structure GPS Co-ordinates and their allowable Clearance Heights.  
  • On vehicle start - up, the Device would audibly ask the Driver “if they have checked Vehicle / Load Height and to enter / update the Tag”.
  • Depending on the Vehicle application / use, other alerts can be programmed into the Device - for example, if where a Tipper Trailer Bin is or a Truck Mounted Crane is still raised when attempting to travel. 
  • If the Vehicle is of a standard known Height that does not change (eg Concrete Agitator, Bus, etc) then simply once the Height of the vehicle is entered then it never needs to be changed. 
  • If the Load or Vehicle Height does change (eg Trailer with Excavator on back) then the Driver can simply enter the Load Height via buttons on the Device or via a Bluetooth.  
  • Once the vehicle is moving, the Device constantly compares the stored Bridge / Structure GPS Co-ordinates / Clearance Height with Vehicle Location Co-ordinates and Height.
  • Should the vehicle Load / Height conflict with a Bridge / Structure on the vehicle’s travel route, the Device will provide audible (and or visual) warnings to the Driver as well as suggest alternative exits / routes.

Over- Dimension Mitigaiton.

  • As for the above, the LSM BridgeSense® Device can also be programmed with other stored Data as required, such as Vehicle / Load Dimensions.
  • As with the other features for the LSM BridgeSense® Device, stored Dimensions (Height / Width) of the Vehicle / Load in the Device would provide Driver alerts should the vehicle route be Over or Under Bridges / Tunnels / Structures that do not comply.
  • Once again, Vehicle / Load and Bridge / Structure GPS Co-ordinates are compared dynamically (as the vehicle travels) without any Pre - route planning required.   

Over- Weight Mitigaiton.

  • Weight / Mass of Vehicle Load can be stored on the Device.
  • As with the other features for the LSM BridgeSense® Device, stored Weight / Mass of the Vehicle / Load in the Device would provide Driver alerts should the vehicle route be Over Bridges / Structures that do not comply.
  • Once again, Vehicle / Load and Bridge / Structure GPS Co-ordinates are compared dynamically (as the vehicle travels) without any Pre - route planning required.   

Other- Capabilities

  • The BridgeSense® Device can also be programmed to Decelerate and / or apply Braking to mitigate an interaction if the Driver ignores the Device warnings- even apply AEB (Automatic Emergency Braking).     
  • Non - compliance / ignoring of warnings can also be stored on the Device. 
  • Where GSM / Telematics is required, then alerts / warnings can also be sent back to base to LSM FSM® Fleet Safety (Tracking) Manager.  
  • Other functions / operations for the LSM BridgeSense® concept can be considered. 
BridgeSense Trans 002.png
LSM BridgeSense® concept- please click to enlarge
Struture 001 800 x 500.jpg
Struture 002 800 x 500.jpg
Bridge Mass- dimension 001 800x500.png
Bridge Impact 003 x 800x500.png
LSM BridgeSense® Key Features + LSM TrainSense®

LSM BridgeSense®- Key Features

Some of the Key Benefits / Features for the LSM BridgeSense® concept are as follows:  

  • The LSM BridgeSense® is a standalone mitigation device that does not require any ongoing subscription or telemetry costs. 
  • No ongoing maintenance, no additional support resources, infrastructure or personnel costs are required. If the LSM TrainSense® Device fails- then it is replaced quickly and simply at low cost.
  • GPS Satellite (not Sat Navigation or App) network is reliable, accurate and covers all of Australia and the World.  
  • Mapped data can be manually updated with data changes or adding additional coordinates for new Overhead structures via either a ESim or BT via PDA / Phone App. Or with the telematics option, can be updated automatically over - the - air
  • It is not a Sat Navigation / Telematics device that requires pre - route planning. LSM BridgeSense® simply compares stored Over-head Structure coordinates / Height data in the Device Tag against the Vehicle’s / Load stored Height data of the vehicle as it is motion- dynamically.  
  • Other features can be designed into the Device Tag, such as telematics for back- to -base reporting (e.g. LSM FSM® Fleet Safety (Tracking) Manager), connection to external devices- eg Tipper Bin / Truck Mounted crane position, other Structure data such as Power lines, etc. 
  • Can be used to provide Deceleration of the vehicle, Braking or even AEB is alerts are ignored.

LSM TrainSense® + LSM BridgeSense® Combination

As with Over- Height Bridge / Structure Impacts, the costs of Railway Level Crossing incidents also cause many $100's of millions for maintenance, emergency response, repairs, traffic delays and injury / fatalities, etc.

Subsequently, it is pragmatic and cost-effective to combine the functions / features of both LSM TrainSense® + LSM BridgeSense® technology's into a Singular Safety Mitigation Device.

Bridge Impact 028 800x500.jpg
Sign 003 800x500.jpg
Sign 004 800x500.jpg
BrdigeSense® Key Features- + LSM TrainSense®


To ensure the effectiveness of the LSM BridgeSense®, it is envisaged that the Vehicle In- Cabin Device / Tag would need to be mandated for every On- Road Heavy / Commercial Vehicle (e.g. Trucks). 

Mandating can simply be provided via legislation / ADR that all On- road Commercial Vehicles Trucks / Heavy Vehicles (new and existing) are to be fitted with LSM BridgeSense® Tag Device.

It is estimated that the LSM BridgeSense® would be a sale price of about AU$25 / each.

Even if LSM BridgeSense® mitigated 50% of Bridge Impacts, the savings to the taxpayer / community would far exceed the device implementation costs.

Not only would LSM BridgeSense® provide significant savings (traffic delays, repairs, emergency response, etc and lives) but also the costs for the LSM BridgeSense® can be recoverable.    

Concept for cost recovery for the LSM BridgeSense® would be: 

  • An increase in Truck registration to recover the outlay for the BridgeSense® Vehicle In- Cabin Tag Device.
  • With a replacement service life of say three (3) years, then the impost to Operator on registration costs of would be calculated as AU$8 / annum and should not be seen as a significant impost.
  • In addition, the concept could be integrated into Vehicles at manufacture.
  • It should also be considered that the LSM BridgeSense® and the LSM TrainSense® be developed as a Singular Vehicle In- Cabin Device that can provide for both On- Road (Over + Under) Bridge and Railway Level Crossing Safety Mitigation Control.


To be effective, it is envisaged that LSM BridgeSense® requires to be installed on all respective Commercial Vehicles and as such, the support of the respective Australian (or International) Government / Authorities is needed to accept /  to fund the development of LSM BridgeSense®.

At this time, it is envisaged that the development costs to be estimated at $1- $2 million and LSM Technologies are seeking such funding at the moment - please Contact Us to start the conversation.

Integration 002 800x500.jpg
Integration 001 800x500.jpg
Find Out More


Phone+61 7 3725 8100