how are the opposite bus stops determined

[lt25106]

theres a blue line between the opposite bus stops

[cheeaun]

Via https://landtransportguru.net/bus-stops/

Most bus stops end with the digit ‘1’ or ‘9’. The last digit is used to differentiate the direction of the services. If it ends with ‘1’ for a service travelling from A to B, the pairing of this bus stop across the road for direction B to A will have a bus stop number ending with ‘9’.

Read more if interested: https://cheeaun.com/blog/2021/09/bus-service-route-diagrams-busrouter-sg/

[lt25106]

Thanks! Also about the last paragraph in your blog:
https://youtu.be/_BURy2_mGZM?t=283

[lt25106]

Also asking, is routes.json more accurate than routes.geojson?

[lt25106]

Which one does busrouter use? I'm trying to draw them on a map but both dont look as accurate as busrouter's (the bus route just goes in the centre of the road instead of on each side)

[cheeaun]

routes.min.json

busrouter-sg/assets/app.js

Lines 42 to 43 in 2d817ce

	const dataPath = 'https://data.busrouter.sg/v1/';
	const routesJSONPath = dataPath + 'routes.min.json';

How do you draw them? And which map tile layer? Screenshots would be useful.

[lt25106]

I'm drawing them with Leaflet and openstreetmap, I tried using routes.json with @mapbox/polyline and L.polyline, and also tried using routes.geojson with L.GeoJSON. Both produce this: (sorry if the orange is hard to see)The bus route is in the centre, while in busrouter.sg it is split into 2 directions:
So which source is busrouter using? Or are the 2 directions calculated using the data?

[cheeaun]

Oh, the lines are shifted.

busrouter-sg/assets/app.js

Lines 2041 to 2051 in 2d817ce

	'line-offset': [
	'interpolate',
	['linear'],
	['zoom'],
	12,
	0,
	16,
	-3,
	22,
	['*', ['zoom'], -3],
	],

line-offset shifts the lines from their center, in pixels, when rendered. The math kinda works like this:

• At zoom level 12, the offset is 0 pixels (the line is not offset).
• At zoom level 16, the offset is -3 pixels (the line shifts by -3 pixels).
• At zoom level 22, the offset is ['*', ['zoom'], -3], the offset becomes the zoom level multiplied by -3 (so at zoom 22, the offset is -66 pixels).