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System for notifying vehicles of changes in Variable Speed Limits (VSL) Disclosure Number: IPCOM000245683D
Publication Date: 2016-Mar-30
Document File: 4 page(s) / 60K

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The Prior Art Database


The invention below outlines a system for notifying vehicles of Variable Speed Limits (VSL) applied to specific sections (and lanes) within a motorway network. The system uses a VSL controller to interact with the vehicles which will display the VSL to the driver within the cabin of the vehicle

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System for notifying vehicles of changes in Variable Speed Limits (VSL)

Many sections of the motorway network in the UK (and abroad) are increasingly being upgraded to 'smart motorways' with the aim of reducing traffic congestion and

improving safety. There are several ways in which this can be achieved including opening the hard shoulder of the motorway as an additional lane for traffic to use as

well as applying a variable speed limit (VSL) displayed on overhead gantries.

    There are different implementations of how VSL's are can be triggered. Some are applied automatically depending on the flow of traffic through the section of smart motorway and others are applied manually by someone in a control center. Although the intention of these VSL's is to reduce congestion by maintaining the flow of traffic, there is the distinct possibility for accidents to occur. Such systems place a large dependency on the driver to alter there speed to the VSL at the point they see the limit on the overhead sign. They then follow that speed until the next overhead sign is in sight and follow that limit. If a vehicle A passes under gantry A

with a VSL set to 50mph then as soon as they get past the gantry it changes to 60mph, car B will now be travelling behind them at 60mph but will need to break more harshly as they approach car A who is still travelling at 50mph as gantry B is not yet in view.

    To avoid the dependancy of the driver having to see the VSL on the gantry to be able to adjust their speed accordingly, the article herein outlines a mechanism for providing in vehicle notifications to the driver at the point the VSL is applied and / or updated.

    The mechanism specifies that the vehicles will receive up to date, in car notifications of changes in speed limit at the point in which the speed limit is changed. The advantage of receiving these notifications is that it will enable to driver to react to the changes in speed limit quicker which will reduce the likelihood of scenarios described in section one from occurring. The in car notification will be made up of an audible and visual signal to the driver.

    Described herein is a mechanism by which the system will detect which cars to broadcast the VSL to i.e cars travelling in the correct direction on the motorway at a specific point of the section of smarter motorway.

    1. Existing mechanisms for controlling and applying the VSL to the overhead gantries will be modified to include making the VSL data available for vehicles to consume. This could be achieved by using existing connected car technologies to transmit the information to the vehicle such as Wifi or 4G networks.

    2. When the car approaches the stretch of motorway where the VSL can be applied it receives a handshake request from the VSL controller. The request from the controller is for the vehicles identifier (could be to the registration number) and the heading of the vehicle i.e. northbound. The vehicle can provide its heading from the o...