As an Uber rideshare vehicle is on a journey, the passenger who booked the trip gets an alert via their mobile phone app.
"Drop off along bike route," the message reads. "Look for people on bikes before opening the door."
The push notification is part of a new feature, called Bike Route Alerts, being rolled out across 18 Australian cities – including all state capitals - by the transportation network company as part of an international initiative.
"These alerts are aimed at preventing 'doorings'," says Dom Taylor of Uber Australia, "which is when people open car doors into a cyclist's path, hitting them or forcing them to dangerously swerve into traffic."
One point of interest: how does the company define a "bike route", given the mixed bag of cycling infrastructure in Australia that can range from random logos and lines on the road to fully separated paths?
"These routes include roads with dedicated cycling infrastructure or lanes, as well as local and national cycleways that are recommended to cyclists but don't have specific infrastructure," says Carissa Simons of Uber.
The Australian rollout follows months of trials of the program in the United States. Uber's competitor in North America, Lyft, has initiated a similar in-app messaging program urging customers to look out for cyclists when alighting a vehicle.
The dangers of 'dooring'
Having a car door opened into your path while riding a bicycle is a terrifying scenario.
The rider can be hurt by the sharp, pointed edges of the door as a vehicle occupant swings it into the roadway, while more injuries can be sustained in a resultant fall.
Most dangerous of all, however, is the chance of falling and being run over from behind by a car or truck. And a rider might not strike the door, but their reflex swerve will put them in the path of other vehicles.
VicRoads reports that between July 2011 and June 2016 there were 771 car doorings involving bike riders. Of these, two were fatalities and 177 were serious injuries. That's just for Victoria, and only involves the incidents reported to authorities.
Avoiding the problem
The first thing to realise about doorings is that it's the responsibility of a vehicle occupant to open a door safely.
The Australian Road Rules state: "A person must not cause a hazard to any person or vehicle by opening a door of a vehicle, leaving a door of a vehicle open, or getting off, or out of, a vehicle."
Roads authorities advise cyclists to look out for people exiting cars, to wear bright clothing and use lights in murky conditions but there's always the chance of getting caught out by someone who simply hasn't taken the time to look before opening the door.
The most obvious way to avoid being doored is never to ride in a vehicle's "door zone".
This can require courage and assertiveness, as drivers approaching from behind may become impatient that you aren't "keeping to the left" – not realising the risks this can involve. Especially when there are bike markings or lines situated in the door zone.
It's worth noting that the minimum distance passing laws now in force in all Australian states (except Victoria) do not apply to cyclists passing cars, whether they are mobile or stationary.
The 'Dutch reach'
In recent years, this curious term has been gaining popularity when describing a method of avoiding dooring incidents.
In essence, it involves a car occupant using the hand that's furthest away from the door to operate the door handle.
This turns the person's head and shoulders towards the door, making it easier for them to look to the rear of the vehicle for any approaching cyclists, while the nearside hand can be used to control the swing of the door.
Uber says it will also roll out an awareness program featuring the Dutch reach in the coming months.
Reaching an audience
Uber says it has 64,000 active drivers and 3.8 million ride share subscribers in Australia - some 15 per cent of the population - although it remains to be seen how many will get a Bike Route Alert message.
Meanwhile, the initiative has been welcomed by cycling groups.
"Dooring is one of the biggest risks to riders but people still often forget to check for bikes, particularly when passengers decide to jump out while the car is sitting in traffic," says Anthea Hargreaves of Bicycle Network. "Uber's latest app feature cannot come soon enough."
Bastien Wallace of Bicycle NSW says her organisation "applauds efforts by Uber to educate passengers in order to make roads safer for bike riders", adding that if data showed the Dutch reach campaign was effective in Australia, "we'd love to see it incorporated into road safety education".
Sydney Morning Herald journalist Michael O'Reilly has written the On Your Bike blog since 2011.