const HEIGHT = 400;

​

const numLanes = 3;

let laneW = WIDTH/(2+numLanes);

​

​

let car1;

function setup() {

  createCanvas(WIDTH, HEIGHT);

  car1 = new Car((1+floor(random(numLanes)))*laneW + laneW/6, 200, 4/6*laneW, 7/6*laneW);

}

​

function draw() {

  background(0, 120, 0);

  // road

  fill(0,0,0);

  rect(laneW, 0, laneW*numLanes, HEIGHT);

  // side lines of road

  stroke(255);

  strokeWeight(3);

  line(laneW, 0, laneW, HEIGHT);

  line(WIDTH - laneW, 0, WIDTH - laneW, HEIGHT);

  // road lanes

  for (let i=1; i<numLanes; i++) {

    stroke(255, 255, 0);

    strokeWeight(3);

    drawingContext.setLineDash([15, 30]);

    line((i+1)*laneW, 0, (i+1)*laneW, HEIGHT);

    drawingContext.setLineDash([]);

    noStroke();

  }

  // draw car

  car1.show();

}