It occurred to me the other day that I occasionally post about how rallies from around the world are conducted, but I have posted very little about the details of American time-speed-distance rallies, mostly because it seems very common place to me. However I am pleased that approximately 30 to 40% of the people who look at this page are from outside the USA and therefore might not be familiar with USA time-speed-distance rallies. This post will attempt to describe, in general, the typical route instructions that American rally competitors must contend with.
The page below is the first page from the recent Covered Bridge Rally. On all of the pages shown in this post I have left my notes in place that I made in pencil during the rally.
Typical First Page Starts With An Odometer Check
The left side column shows route instruction number. These are frequently called the NRI (Numbered Route Instructions). The NRIs from 1 to 11 are for the odometer check at the start of the rally. There is no separate measured distance for competitors to make multiple odometer runs to calibrate their odometer prior to the rally. In this case, competitors are told in NRI 1 that they have 30 minutes to complete the 12.23 mile odometer check at NRI 11. We were running in the Stock Class in this rally using the standard automobile trip odometer with a digital 1/10 mile display. Stock Class competitors must estimate the 1/100 mile number. For our car, I can see from the notes on this page that the Chevrolet’s trip odometer indicated a distance of 12.28 miles when the rallymaster’s distance was 12.19 miles. As a result our estimated Odometer Factor was 0.99267.
I have indicated the meaning of the acronyms in red notes added to the page. Two important points to remember is that in USA rallies all of the controls or check points are hidden and times are measured/scored in 1/100 minute units. Therefore you have to be running on time, all the time. Typically time controls are located just over a hill or just around a corner or bend in the road and therefore appear very suddenly. Creeping approaching the timing line at a control or check point is not allowed as the minimum rally speed is 1/2 of the required average speed.
A Transit Zone is defined as a portion of the rally where the teams are given a defined time to travel a given route and distance. There will be no controls or check points in a Transit Zone. A Free Zone is a portion of the rally where the teams must follow the instructions and stay on time, but there will be no controls or check points in a Free Zone.
The other acronym on the above page is CAS. This can be said to have two meanings – either Continue Average Speed or Change Average Speed, which effectively both mean the same thing – proceed at the average speed stated.
A typical page from the route instructions is shown below.
Typical Rally Instructions From Covered Bridge Rally
On the page above, it can be seen that in USA rallies, the required average speeds are almost constantly changing. Also the distances or mileages to many instructions are not provided, therefore the navigators have to measure the rally as well as provide the driver with route following instructions. For me running in this particular rally, as we were running in the Stock Class, I had to carefully watch the car’s odometer, as I had to determine and record the distance at locations of speed changes without the benefit of a “freeze” feature on the odometer. This was the basis for the timing calculations which had to be done separately.
As the timing units used in USA rallies are 1/100 of a minute, an instruction saying “Pause 10” means pausing 0.10 minute or 6 seconds. Pauses are typically provided at locations such as stop signs onto a busy road.
Another unique aspect to the Covered Bridge Rally are the average speeds that the teams are to follow are rather strange speeds often presented to four places of decimal. While at first glance these seem weird, these speeds actually work out to very simple minutes per mile factors, which make it easier for navigators doing manual calculations.
In the New England area, we often use a slightly different style of route instructions, such as shown below in a typical sheet from the recent Big Lap Rally.
Typical Route Instruction Page From The Big Lap Rally
As can be seen, the core of the route instructions in this rally were presented using tulip diagrams. The other difference is that for some instructions the total mileage or the incremental mileage is provided. On the route instructions above, the “X” would represent the location of the referenced sign. As with the Covered Bridge Rally, many mileages are not provided. As with the Covered Bridge Rally, all time controls are hidden, so we have to run on time, all the time.
The fact that all controls are hidden and that there are constantly changing average speeds make the timing quite challenging as all of the timing calculations have to be done while measuring the rally distances and giving the driver route following instructions make the rally navigator’s job quite busy.