correct ..... If you notice the location of the drain is not in the centre of the road but over the far right side possible 3/4 of the total road width at least, although it's not on the edge of the roadway, I can only presume that the location of the pipe installation was put there was either something prevented the pipe running alone the far edge of the road such as another pipe or underground service and the location was not absolutely paramount at the design stage. And yes, you'll notice the road does slope slightly from the centre out.