chart = Plot.plot({
height: 100 + new Set(traffic.map(d => d.name)).size * 100,
width,
marginBottom: 5,
marginLeft: 120,
x: {axis: "both"},
y: {axis: null, range: [6 * 10 - 2, (2.5 - overlap) * 17 - 2]},
fy: {label: null, domain: traffic.map(d => d.name)},
marks: [
d3.groups(traffic, d => d.name).map(([, values]) => [
Plot.areaY(values, {x: "date", y: "value", fy: "name", curve: "basis", sort: "date", fill: "#495867"}),
Plot.lineY(values, {x: "date", y: "value", fy: "name", curve: "basis", sort: "date", strokeWidth: 1})
])
]
})