End the most common form of littering
with one of the oldest forms of communication

Smoke
Signals

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a hand putting out a cigarette butt in the machine, a smoke ring rises from the top of the machine

Where there's smoking,
there's litter

Telling people what to do is easy. Changing people’s behavior is hard. Cigarette butts are the most widespread form of littering. Since smoking is prohibited in outdoor seating areas and outside venues where ashtrays used to be available, smokers simply step outside to smoke in the streets. This has turned our streets into ashtrays, causing both significant environmental damage and an unpleasant urban environment.

Keeping Malmö clean comes at a striking annual cost of

SEK
80,000,000

Solving an age-old problem by prompting behavioral change

Smokers don’t want to litter. They just want a cigarette. But the available ashtrays on lampposts and bins disappear in the cityscape. And when the right choice is invisible, the wrong one becomes a habit.

Increased cleaning, rules and regulations had all proven insufficient to disrupt the smokers’ old ways. So, The City of Malmö stopped telling people what to do and started showing them how they could both smoke and discard their cigarettes the right way.

Using a solution that quite literally rises above the noise of everyday life – smoke signals. One of the world’s oldest forms of communication, now rekindled to signal that cigarette butts belong in ashtrays.

A smoke ring floating in the clear blue sky.Blue sky with a circular smoke ring and part of a large blue machine and some leaves in the foreground.White smoke ring floating against a clear blue sky with tree leaves in the top left corner.Smoke ring floating upward against a clear blue sky with tree branches in the upper left corner.
A smoke ring floating in the clear blue sky.
A smoke ring floating in the clear blue sky.
A smoke ring floating in the clear blue sky.
A smoke ring floating in the clear blue sky.

Smoke signals are the new visual language in Malmö for reaching smokers, using positive signals instead of prohibition.

Want to end the littering in your city too? Use the open-source material on this site.

“Traditional approaches like more ashtrays, warning signs, or fines underperform because they instruct people on what to do but fail to show that others are doing it.”

— Niklas Laninge, Psychologist and co-author of the report

image shows a person looking up at the blue smoke signals machine placed on a square in Malmö, Sweden
a circular wavy shape that reads 'DOWNLOAD REPORT' around the perimeterdownload-icon

Behavioral
studies – the genesis of why it works

Solutions are often based on assumptions. But behavior-changing design must be based on real evidence. That’s why a preventive approach rooted in behavioral science was needed, grounded in how the environment around us shapes the choices we make. And that’s why this project began with a report outlining three principles for solutions that ignite behavioral change.

a person looking up at the smoke signals machine inside a workshop
Circular smoke ring illustration with 'DOWNLOAD BLUEPRINT' around the perimeter.download-icon

A signal system designed from the three principles

Smoke signals combine all three principles of the report in an integration of behavioral design, innovation, and ancient communication.

An image of the number '1'

principle

Visibility

The right alternative must be clearly noticeable and not blend into the urban environment.

Illuminated round sign with text 'RÖK HÄR' mounted on a pole at dusk with tree branches and building silhouettes in the background.

Smoke Here

A guiding light

Signs and ashtrays mounted on streetlights, leading the way towards the correct disposal of cigarette butts.

Blue cigarette butt receptacle attached to a pole with the text 'FIMPA HÄR'.

Discard cigarette butts here

Drawing new shapes from ancient ways

Here, the smoke signals are used in a pictographic way.

Colors of guidance

The consistent blue color is RAL 5005, also known as Signal Blue which is commonly used in mandatory signs, indicating a required behavior rather than prohibition.

This color was chosen to communicate positive instructions and specific required actions during the 1968 Vienna Convention on Road Signs and Signals.

Lighting built to be seen

During the darker hours of the day, the text is backlit, further enhancing visibility.

The text 'RÖK HÄR' inside a wavy circular outline on a black background. Illustration labeled 'Shape'.
The text 'RÖK HÄR' on a blue background surrounded by a white, wave, circular shape. The label reads 'Color'.
The text 'RÖK HÄR' on a blue background surrounded by a white, wave, circular shape. The white shape is illuminated by a soft glow. The label reads 'Light'
The text 'RÖK HÄR' inside a wavy circular outline on a black background. Illustration labeled 'Shape'.
The text 'RÖK HÄR' on a blue background surrounded by a white, wave, circular shape. The label reads 'Color'.
The text 'RÖK HÄR' on a blue background surrounded by a white, wave, circular shape. The white shape is illuminated by a soft glow. The label reads 'Light'
Stack of square blue and white coasters with 'Följ rökringen till rökningen' on a blue background and a smoke ring in the center.
Stack of square blue and white coasters with 'Följ rökringen till rökningen' on a blue background and a smoke ring in the center.
An image of the number '2'

principle

Norms

Social norms shape behavior — show that others use the ashtray, and the rest will follow.

a hand putting out a cigarette butt in the machinepeople smoking in front of the machine at nighta smoke ring rising form the machine at night

A beacon crafted for social signals

This monument features a built-in ashtray with an IR sensor that releases a smoke ring into the sky every time a smoker discards their cigarette there. The logic? Social proof. This touchpoint enables smokers to signal to each other, “This is the right place to smoke” – so that fewer cigarette butts are disposed of in the wrong way.

Every signal is unique, shaped by wind and weather, yet with an unmistakable, characteristic form: a round, white ring of smoke transforming an individual action into a public cue. A brief, theatrical burst and a playful reward for the right choice.

10.29.2025      Version 1.0

Smoke
Signals

In use at Möllevångstorget, Malmö

Measurements:
3,200x2,400x2,400 mm
Weight:
422 kg
Color:
Signal blue (RAL 5005)
Placement:
Möllevångstorget, Malmö
Capacity:
3,000 cigarette butts

Mod. 1.4
Ext. environment and scale

Blueprint-style image showing a bicycle, a standing woman, the smoke signal machine, a man looking at a phone, and a seated woman on a bench with a scale at the bottom.

Mod. 1.3
Int. mechanics

Technical blueprint diagram of a cigarette disposal machine with labeled parts including LED lighting, smoke chamber, baffle, piston, belt, rotor, ashtray, tube, IR sensor, cigarette collection hatch, collection bin, and non-slip ground plate.

Mod. 1.1
Ext. sides

Top view of the smoke signals machine, showing the non-slip base plate with the text 'RÖK HÄR' around the perimeter.

Mod. 1.2
Ext. top

Top view of the smoke signals machine, showing the non-slip base plate with the text 'RÖK HÄR' around the perimeter.

10.29.2025

Version 1.0

Smoke
Signals

In use at möllevångstorget, Malmö

External meas's:
3200x2400x2400 mm
Weight:
422 kg
Color:
Signal blue (RAL 5005)
Placement:
Möllevångstorget, Malmö
Capacity:
3000 cigarette butts

Mod. 1.4
Ext. environment and scale

a labeled side view showing the inside of the smoke signal machine, labels include 'LED light ring, smoke chamber, baffle, piston, non slip ground plate, etc.'

Mod. 1.4
Ext. environment and scale

a side view showing the front and back of the smoke signals machine

Mod. 1.4
Ext. environment and scale

Top view of the smoke signals machine showing the non-slip baseplate with cut out text that reads 'RÖK HÄR'
An image of the number '3'

principle

proximity

The distance to the ashtray is crucial — place the intervention exactly where the problem occurs.

two people drinking beer at a bar looking at the machine on the square outside the window
Stack of square blue and white coasters with 'Följ rökringen till rökningen' on a blue background and a smoke ring in the center.

Messaging at the point of decision

Posters and coasters placed at venues surrounding the focus area. Reaching smokers before they step outside for a smoke with an inviting messaging and the same visual language as the installations on the street.


Follow the smoke ring to the smoking.
A signal for where you discard your cigarette butts in Möllan.

Stack of square blue and white coasters with 'Följ rökringen till rökningen' on a blue background and a smoke ring in the center.

Follow the smoke ring to the smoking.
A signal for where you discard your cigarette butts in Möllan.

Swedish anti-smoking poster with white text 'Följ rökringen till rökningen' on a blue background and a smoke ring in the center.Anti-smoking poster with a smoke ring against a blue sky, the text reads FÖLJ RÖKRINGEN TILL RÖKNINGEN/FOLLOW THE SMOKE RING TO THE SMOKINGAnti-smoking poster with a smoke ring against a blue sky, the text reads FÖLJ RÖKRINGEN TILL RÖKNINGEN/FOLLOW THE SMOKE RING TO THE SMOKINGAnti-smoking poster with a smoke ring against a blue sky, the text reads FÖLJ RÖKRINGEN TILL RÖKNINGEN/FOLLOW THE SMOKE RING TO THE SMOKINGAnti-smoking poster with a smoke ring against a blue sky, the text reads FÖLJ RÖKRINGEN TILL RÖKNINGEN/FOLLOW THE SMOKE RING TO THE SMOKINGAnti-smoking poster with a smoke ring against a blue sky, the text reads FÖLJ RÖKRINGEN TILL RÖKNINGEN/FOLLOW THE SMOKE RING TO THE SMOKINGAnti-smoking poster with a smoke ring against a blue sky, the text reads FÖLJ RÖKRINGEN TILL RÖKNINGEN/FOLLOW THE SMOKE RING TO THE SMOKINGAnti-smoking poster with a smoke ring against a blue sky, the text reads FÖLJ RÖKRINGEN TILL RÖKNINGEN/FOLLOW THE SMOKE RING TO THE SMOKINGAnti-smoking poster with a smoke ring against a blue sky, the text reads FÖLJ RÖKRINGEN TILL RÖKNINGEN/FOLLOW THE SMOKE RING TO THE SMOKINGAnti-smoking poster with a smoke ring against a blue sky, the text reads FÖLJ RÖKRINGEN TILL RÖKNINGEN/FOLLOW THE SMOKE RING TO THE SMOKING
people walking by the smoke signals machine at night

The results:

9 out of 10
smokers followed
the smoke signals
– and chose the
ashtrays.

144%

more smokers discarded their cigarette correctly.

17,2oo

cigarette butts were collected in total over only 7 weeks.

SEK 825,000

in potential savings based on the cleaning cost of approximately SEK 4 per cigarette butt. This represents potential annual savings of over SEK 825,000 for The City of Malmö.

17,2oo,ooo

liters of water protected from microplastics, heavy metals and cancerous chemicals.

A cigarette butt is small. But the forces shaping the behavior behind littering are not. Smoke signals make doing what’s right feel good by sparking new social norms into action.