Ratio of Average Bikers versus Miles of Bike Lanes 2004-2012

Sourced from the 2012 DC Bicycle Count Summary, visualized with d3js.

<!DOCTYPE html>
<meta charset="utf-8">
<style>

body {
  font: 10px sans-serif;
}

.axis path,
.axis line {
  fill: none;
  stroke: #000;
  shape-rendering: crispEdges;
}

path.line {
    stroke-width:4;
    fill:none;
    stroke:darkblue;
}

</style>
<body>
<script src="https://d3js.org/d3.v3.js"></script>
<script>

var margin = {top: 20, right: 20, bottom: 30, left: 50},
    width = 960 - margin.left - margin.right,
    height = 500 - margin.top - margin.bottom;

var parseDate = d3.time.format("%Y").parse,
    formatPercent = d3.format(".0%");

var x = d3.time.scale()
    .range([0, width]);

var y = d3.scale.linear()
    .range([height, 0]);

var xAxis = d3.svg.axis()
    .scale(x)
    .orient("bottom");

var yAxis = d3.svg.axis()
    .scale(y)
    .orient("left")
    .tickFormat(formatPercent);

var svg = d3.select("body").append("svg")
    .attr("width", width + margin.left + margin.right)
    .attr("height", height + margin.top + margin.bottom)
  .append("g")
    .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

var line = d3.svg.line()
    .x(function(d) { return x(d.date); })
    .y(function(d) { return y(d.ratio); });

d3.csv("peak.csv", function(error, data) {
  data.forEach(function(d) {
    d.date = parseDate(d.year);
    d.ratio = +d['Peak Hour'] / +d['Miles of Bike Lanes'];
  });

x.domain(d3.extent(data, function(d) { return d.date; }));
  y.domain(d3.extent(data, function(d) { return d.ratio; }));

var l = svg.selectAll(".browser")
      .data([data])
    .enter().append("g")
      .attr("class", "browser");

l.append("path")
      .attr("class", "line")
      .attr("d", line);

svg.append("g")
      .attr("class", "x axis")
      .attr("transform", "translate(0," + height + ")")
      .call(xAxis);

svg.append("g")
      .attr("class", "y axis")
      .call(yAxis);
});

</script>

Modified http://d3js.org/d3.v3.js to a secure url

https://d3js.org/d3.v3.js