Here's a first pass at a lap chart for the 2011 European Grand Prix:
The nodes are sized inversely proportional to the number of laps the car is behind the lead lap (i.e. the number of times they have been lapped by the race leader) and coloured according to stint (so a colour change indicates a pit stop). Crossed lines show a change in race position.
Here's the lapchart, coloured by tyre selection and sized inversely proportionally to the number of stops (would this be more effective if it was sized *proportionally to stops?):
The next chart is a variant of the lap chart showing track position at the end of each lap ("track position lap chart"?). Node colouring and sizing is as for the traditional lap chart.
The aim of this chart is to help try to identify laps on which track position may have been important in the progress of the race.
The following view uses the "time to leader on track" measure for the y-axis; that is, the time (on track) the leader is ahead of each car. This essentially uses the y-scale to add information that the "track position lap chart" doesn't convey, specifically the distance between cars on track.
What's missing, of course, is the time between the lead car and the backmarker - maybe I need to show the backmarker twice in each lap, but keep the y=0 line fixed relative to the leader?
This variant of the track position lapchart uses clour to denote tyre selection and size to denote the number of pit stops:
The downside, of course, is now we can't see who's been lapped. HEre's how the chart looks if we size nodes inversely proportionally to number of laps behind:
What we lose here is a depiction of when a car pits. (Maybe a symbol change would be sensible to denote pit stop?)