Old style slot car race tracks had a maximum lane spacing of 4" which was fine at the time because the maximum width of 24th scale cars was then 3". The older tracks also had very narrow "gutters" - the space between the outside lanes and the retaining walls. Modern 1/24th scale slot cars are now allowed a maximum width of 3¼" for the front and rear tires and body. Champion, Parma and Slick 7 all manufacture tech tools which check this measurement accurately. Because they are wider, and due to the popularity of the larger size 4.5" NASCARS, Supertrucks, a few GTP models and some models of hard plastic model racing, today’s lane spacing for tracks has also been increased. Most are now 4.25" to 4.5" apart.

In addition, modern-day track builders are allowing for much wider "gutters" - some up to 6" to the outside wall; 3" to the inside, now making tracks anywhere from 40" or 41" wide across the racing surface. The only difficulty which has come about with wider surfaces and expanded lane spacing is the difficulty of turn marshalling the far inside lanes, especially by the youngsters who can sometimes have a problem reaching all the way across the track without laying on it. (Warn everyone to keep their shirts tucked in!)

It will be helpful if you will construct a simple "guide" to mark where your lanes will be across the surface to prevent installing sheet rock screws, staples or nails from being installed anywhere near where the router will cut the slots and braid recesses. (See Illustration #5.)