The M4 is a 40 kilometre motorway which extends from Concord in Sydney’s inner west to Lapstone at the foothills of the Blue Mountains. While the M4 Motorway was previously a toll road, on 16 February 2010 the toll was removed and the operation of the road was handed back to the NSW Government.
Travel Time information on the M4
Travel time information is now available on the M4. The travel time system uses roadside electronic signs to display the estimated length of time it should take to reach upcoming motorway exits, based on current traffic flow.
If you are travelling on the M4 you may see the travel time estimates displayed on fixed electronic message signs. Typical travel time messages will include two upcoming exits with estimated times. For example, the image below shows the estimated time to travel from the message sign to the Church Street exit is eight minutes and from the message sign to the Concord Road exit is 15 minutes.
Frequently asked questions
What are the ‘EST. TIME TO EXIT’ messages displayed on electronic signs on the M4?
If you are travelling on the M4 you may see travel time estimates displayed on fixed electronic message signs. The system calculates estimates of how long it should take road users to reach certain motorway exits, based on the current traffic flow. For example, the image below shows the estimated time to travel from the message sign to the Church Street exit is eight minutes and from the message sign to the Concord Road exit is 15 fifteen minutes.
What are the ‘SIGN UNDER TEST’ messages displayed on electronic signs on the M4?
Nine new electronic message signs have been built along the M4. These complement five existing signs to provide a comprehensive travel time information system on the M4. The new signs will be progressively tested and integrated into the M4 travel time information system. The purpose is to test each new electronic message sign in real conditions. During the testing phase for the new electronic signs, the following message will be presented: SIGN UNDER TEST. Various messages may also be displayed.
What is travel time?
The travel time system displays the estimated length of time it should take to reach upcoming motorway exits, based on current traffic flow. On the M4, travel time estimates are updated on electronic message signs every three minutes to reflect current travel conditions and provide the most accurate estimates.
How does travel time technology work?
The technology on the M4 works with regularly spaced in-road loops which detect average vehicle speeds. Every three minutes a computer averages these speeds and calculates the time to travel along various sections of the M4. Additionally, eight electronic readers have been installed at key locations along the M4 to survey the new system.
How many in-road loops are there?
There are in-road loops in each lane of the M4 spaced at about 500 metres which enable travel time estimates for road users in both directions.
How often are the times updated?
Estimated travel times are refreshed and displayed on the M4 motorway electronic message signs every three minutes.
When are travel times displayed?
The M4 travel time system will normally operate between 4am and 10pm each day, seven days a week.
Are there occasions when M4 travel time estimates will not be displayed?
If there is a special event, incident, road work or heavy traffic on the M4 causing a significant impact, the electronic message signs may be used to communicate information about incidents or traffic conditions, rather than travel time estimates.
What does it mean when the electronic message signs are blank?
The travel time signs may appear blank during routine maintenance or if there has been a power or equipment failure or during repair.