Edinburgh, after dark

Every council knows where its lamps are. Nobody measures the light on the pavement.

Leerie turns a phone into a street light meter, maps how dark each street really is, and tells the council which ones to fix first.

Open the live mapWhy it matters

Step 1 · Walk

Any phone becomes a light meter.

Point the camera ahead and walk. Leerie reads the shutter speed and ISO to undo auto-exposure, and keeps one number a second. The picture never leaves the phone.

Step 2 · Map

Mapped street by street.

See where we measured light across Edinburgh and where nearby readings support an estimate.

See the map

Why it matters

After dark, the same street is a different street.

50%

of women felt unsafe walking alone after dark on a quiet street near home, compared with 17% of men.

ONS, Great Britain, 2022
82%

of women felt unsafe walking alone after dark in a park or open space, compared with 42% of men.

ONS, Great Britain, 2022
71%

of women in Scotland felt safe walking alone in their neighbourhood after dark, compared with 90% of men.

Scottish Household Survey, 2025
38%

of women aged 16 to 34 reported catcalling in the previous 12 months.

ONS, Great Britain, 2022

A randomised trial in New York City public housing estimated that extra lighting reduced serious crimes outdoors at night by at least 36%.

A lamp inventory shows where the posts are. Measurements can reveal where a failed lamp, a tree or a long gap between posts leaves the pavement dark. Chalfin et al., NBER

How it works

A phone, a walk and a map a council can act on.

  1. 01

    Walk

    Open the app, point the camera ahead and walk. Leerie undoes auto-exposure with the camera's own shutter speed, ISO and aperture, the method the phyphox lab app uses, and uploads one reading a second with its GPS point. Comfortable and Uncomfortable buttons record how a street feels.

  2. 02

    Map

    Readings are matched to OpenStreetMap streets and compared with nearby measurements. A street at +1 stop has twice the light of its local median. Where nearby readings support an estimate, unmeasured streets appear faded.

  3. 03

    Decide

    Draw an area and set a budget. Leerie maps proposed lamp sites, estimates their effect, and exports the coordinates. It also highlights lighting hotspots and streets worth surveying next.

The lamp map vs the light map

A lamp on a map is not light on the pavement.

George Square to King's Buildings

Council lamp posts, George Square to King's Buildings
What the council's map showsThe council inventory shows where lamp posts are installed.
Measured light by street, George Square to King's Buildings
What we measuredMeasured light varies from street to street. Amber is brighter, violet is darker, and faded lines show estimates.

Around Findhorn Place

Council lamp posts, Around Findhorn Place
What the council's map showsCouncil records show lamp posts on both sides of the street.
Measured light by street, Around Findhorn Place
What we measuredIn this survey view, Findhorn Place appears darker than the streets around it.

Night survey

One night mapping Edinburgh.

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Explore the map
“O Leerie, I'll go round at night and light the lamps with you!”

Robert Louis Stevenson, The Lamplighter, 1885. Leerie was the man who lit Edinburgh's gas lamps each evening. We took that idea back to the streets with a phone light meter.

Privacy

It measures streets, not people.

No photos
Frames are reduced to one brightness number on the phone and thrown away.
No accounts
Each walk gets a random ID. There is no name, email or phone number.
Write-only app
The app can add readings but cannot read anyone's, including its own.
Streets, not people
The map shows per-street summaries. Nobody's path or individual report is ever shown.

Brightness is relative, not lux. A brighter street is not a promise of safety, and Leerie does not predict crime.