Tutorial

INTRODUCTION TO ROAD RALLYING

Mario Barbacci

Richard A. Lerner

Barbara J. Staudt

Chuck Weinstock

April 1989

Modifications by Bob Glickstein

March 1990

HTMLed by Esther Filderman, March 1993

...in which our heroes make feeble attempts to explain the mysterious activities that have kept them away from home and family for many a Sunday -- or so they claim...

If you take a Sunday afternoon drive through the back roads of Western Pennsylvania, you might have noticed some folks driving around, making turns and speed changes for no apparent good reason. Often you will see them stopping at intersections with looks of complete consternation in their faces. If you get close you might overhear discussions along the following lines:

Driver: There was no grass on that triangle, so it was right to turn left at the T.
Passenger: Ah yes, but the MRD in effect said to keep turning right at T until we see the third sailor with a cowboy hat. We saw three sailors, didn't we?
Driver: The last one was not a sailor. That was an admiral. It does not count... does it??
Passenger: Hmm. (Craning neck to see the admiral/sailor.)

What you are observing is a typical rally in progress, with a driver/navigator team in steady state (that is, lost).

1. What is a TSD Rally?

The Blue Ridge Mountain Sports Car Club (BRMSCC) sponsors time-speed-distance (TSD) rallies monthly (except December). A TSD rally consists of a set of instructions specifying a route to travel, and a speed at which to travel. A team, consisting of a driver and a navigator, attempt to travel the specified route at exactly the specified speeds. A TSD rally is not a race; traveling too fast results in penalties as does traveling too slowly. The rally routes generally travel over lightly traveled rural roads in the scenic Pennsylvania countryside.

BRMSCC strongly encourages the participation of novice rallyists. Although there is no Novice Class, special awards are presented to the best Novice crew. There are other rallies sponsored on a regional or national level for experts only.

BRMSCC rallies are generally around 60 miles long and take about 3 hours to complete. Registration usually begins 1 hour before the rally. Driving to and from the rally can take anywhere from 30 minutes to 1 hour, depending on where it starts and where you live. The rally usually begins at a fast food eating establishment and ends at a restaurant, so you should expect to spend the entire afternoon rallying. Eating with us is optional.

Most of this paper is devoted to describing the basics of rallying. There are sections at the end describing common traps, more advanced timing calculations, example route instructions, and a summary page.

2. The Basics of Rallying

There are basically six parts to rallying: starting, odometer calibration, course following, checkpoints, DYLs and speed calculations.

2.1 The Start

At registration, each team is supplied with instructions defining the rally route and any regulations specific to the rally. Both team members should read everything carefully and ask questions. The rallymaster and others are very willing to provide explanations. However, if you ask questions specifically about the rally, the rallymaster may choose to answer with only ``yes'', ``no'', or ``does not occur''. It is important that you register early to give yourselves ample time to carefully read the instructions and make sure that you understand everything. Often teams go to a nearby fast-food restaurant and read the instructions over lunch.

At some point you must set your (digital) watch to the official time of day. It is important that you leave checkpoints at the official departure time. If your watch is off by 30 seconds, you may take the right time to traverse a leg, but you will still end up with a 50 point penalty, because all timing is done using official clocks. An official clock will be available at the registration location. Note that all timing in BRMSCC rallies is done in minutes and hundredths of minutes, not seconds. If the official clock displays 02.30, the time is two minutes and eighteen seconds past the hour; the hour is not shown. Once you have set your watch and are sure that you have no more questions (of course, questions have a way of popping up once you are on the road), you are ready to start out on the rally.

2.2 The Odometer Calibration Zone

The first part of every rally is an Odometer Calibration Zone (OCZ). The OCZ allows each team to correlate their odometer with the odometer used by the rallymaster. This is important since an instruction may have you turn at a specified mileage. Even if your odometer is accurate, the rallymaster's may be off significantly and you may miss the turn. Also, as we will see later, scoring is computed based on the rallymaster's mileage.

An OCZ is about 10 miles long and is generally extremely simple, with very explicit instructions. Before beginning the OCZ, you should zero your trip-odometer, or note your odometer reading to the hundredth of a mile (just guess), at the marker designated as the start of the rally. At the end of the OCZ you are told what the official distance was. Compare your mileage with the official mileage to get a calibration factor. The equation to use is:

Your Milage

--------------

Official Milage

Then, multiply each mileage in the instructions by this number to get the mileage that your odometer will read when you are at the official mileage. If your odometer reads 9.60 miles at the end of the OCZ, and the official mileage is 10.00, your calibration factor is .96. If a route instruction is referenced to mile 2.00, you should execute that instruction when your odometer reads 1.92 (.96*2.00). Note that you should always try to read your odometer in hundredths of miles. Assuming you have a tenth-reading odometer, the accuracy with which hundredths can be guessed is surprising.

Somewhere in the rally instructions, you will be told when to start the rally and how much time to take to complete the OCZ. From this information you can determine at what time you should leave the end of the OCZ and start the competition portion. For instance, a rally might start at 2:00pm plus your car number in minutes and require 20 minutes to reach the ``End OCZ'' instruction. If you are car number 5, you would leave the OCZ at 2:25pm. Beware of traps here. Some common timing traps are described in the section on Traps.

Unless the rally instructions say otherwise, you can start the OCZ whenever you are ready. You can give yourselves some extra time at the end of the OCZ by starting it early. However, remember to wait at the end of the OCZ until the proper time.

2.3 Course Following (route instructions)

The primary goal of rallying is to follow the route laid out by the rallymaster. At the start of the rally you are given a sequence of instructions, most of which specify the turns necessary to follow the route (the rest provide additional information such as the speed to drive). A typical instruction will tell you in what direction to go and when to apply the instruction:

25. Right at T.

[This means turn right when you reach an intersection that looks roughly like a T. You must be on the road that is ending to use this instruction.]

26. Left at STOP.

[This means turn left when you encounter a stop sign that requires you to stop.]

27. Straight at ``stop''.

This means go straight when you see a sign that has the word ``stop'' written on it. This could be a stop sign, a bus stop sign, a sign that says ``Stop at Joe's'', etc.]

1.63 28. Left.

This means go left when you have gone 1.63 miles from the last time you zeroed your odometer. The mileages are written in the margins, to the left of the instruction number.]

The route instructions must be executed in ascending numerical order; watch for instructions written out of order. More importantly, one instruction must be completely executed before its successor may be begun.

Words that are quoted refer to signs. A sign may be quoted in its entirety, or only partially, but quoted words should be obvious, not fine print. Capitalization and punctuation may be different than on the sign, but the spelling must be identical. Instructions with unquoted words refer to landmarks, like church, red mailbox, etc. It is extremely important to read instructions precisely. For instance,

5. Left at stop.

may mean something different than

5. Left at ``stop''.

The first refers to a stop sign that requires the rally car to stop. The second refers to any sign that includes the word ``stop'', including stop signs. Similarly,

6. Left after Smith Rd.

may mean something different than

6. Left after ``Smith Rd.''

The first indicates that you should turn left after passing Smith Rd. The second requires you to make the first left after a sign that says ``Smith Rd.'' This may cause you to turn on Smith Rd. if the sign appears before the road at the intersection. The BRMSCC rally regulations contains a glossary that precisely defines such words as ``at'', ``before'', ``turn'', etc. These definitions must be followed precisely by the rallyist. [Note: Since this tutorial was written, the club ceased to use a global glossary. Each rally master includes one with the general instruction on every event.]

A route instruction may be referenced to an official mileage, noted in the left margin next to the instruction (see instruction #28 above). These instructions must be executed within a tenth of a mile of the given mileage. Remember to correct all mileages for your odometer. Do not execute this instruction before you reach the mileage. If you are fairly confident that you have reached the mileage, but you cannot make the turn (e.g. you are not at an intersection) you are probably off course. You should retrace your steps looking for mistakes (see the section on off-course excursions).

The route instructions will also contain non-course-directing instructions. These instructions do not direct your course of travel. The most common of these specify speed changes (CAS instructions) and pauses. These will be described later, but for now, note that all non-course-directing instructions should be executed when their minimum conditions are met; if you are told to CAS 40 at ``Tavern'', change your speed at the sign, not the next intersection.

Another common instruction is the mileage reference. These instructions are often used to verify that you are on-course, particularly during the OCZ. The following instructions are mileage references and do not instruct you to make any course directing actions; do not turn at mileage references.

2.23 3. M.R. ``Bedford Lane''.

[Look for sign containing ``Bedford Lane'' at 2.23 official miles.]

6.40 8. Church.

[Look for a church at 6.40 official miles.]

2.4 Course Following (main road determinants)

Route instructions make up only one part of course following. In addition, each rally lists main road rules that specify which direction to go at each intersection. Common sense might tell you to continue straight until an instruction tells you to do otherwise. Another way of stating this would be: ``at each intersection, the main road goes straight''. This type of rule is stated as a main road determinant (MRD). A list of active MRDs define how to proceed through intersections that are not specifically described in the route instructions. The general instructions for each rally indicate the active MRDs and their priorities. Typical MRDs include the following:

Straight as possible
The main road is the road that is most directly ahead.
Left at T
At a T, the main road goes left. Note that an intersection can only be considered a T if the road you are on ends and you can go either left or right.
Protection
The main road is the single road leaving the intersection that does not have a stop or yield sign, excluding the road you entered the intersection on. This is a very common MRD and causes a lot of trouble for novices. In particular, if you see the back of a sign requiring oncoming traffic to stop or yield, look very carefully for signs on the roads to either side. If exactly one of them does not have a sign, that is the main road by protection. Likewise, when approaching a T from the base (your road ends), look for stop or yield signs. Remember, you are expected to be able to recognize these signs from the back by their shapes (even if mostly hidden by trees, etc.).
Onto
If a route instruction tells you to follow a road using the term ``onto'' and its name or number, then the main road is the road leaving the intersection with that name or number. Watch for jogs to the left or right of the onto road.

It is very important to consider the MRDs at each intersection, and to apply them in the order specified by the rallymaster. It is also important to consider the next route instruction at each intersection. Unless specified otherwise, you should consider route instructions and MRDs in the following order:

1. Execute the next route instruction if it is referenced to a mileage, at that mileage.

2. Execute the next route instruction, only if it takes you off the Main Road as defined by (3).

3. Follow the main road, as defined by the MRDs.

Unless otherwise instructed, a course-directing route instruction that is not referenced to an official mileage may only be executed if it forces you to leave the main road. If a route instruction directs you in the same direction as the main road, then going through that intersection constitutes use of a MRD, not the route instruction. For example, suppose the MRDs are:

1. Right at T.
2. Straight as possible.

Suppose the next route instruction is ``Right at stop.'' Now you come to a T with a stop sign. You should turn right, using the MRD ``Right at T''. Since the main road goes the same direction as the route instruction specifies, you are using the MRD, not the route instruction. After the turn you are still looking for a stop sign at which to turn right. Now if you reach a crossroad with a stop sign, you should go right there using the route instruction. If an instruction has a mileage to the left of it, in the margin, this rule does not apply. When you arrive at the mileage, you execute the instruction regardless of the main road.

If an instruction simply says ``turn'', it means that you should leave an intersection on a road other than the main road. Thus, if you approach a T and have the MRDs mentioned above, the main road goes to the right; to execute the turn instruction, you must leave the main road by turning left. You can execute a turn instruction only if there is a unique road to the left or right other than the main road.

2.5 Off-Course Excursions

Even experienced rallyists occasionally find themselves off-course. For first time rallyists this may be their steady state. Not to worry! Once you realize that you are off-course, you should simply retrace your steps, inspecting your decisions at every intersection, until you find your mistake or reach a point that you know is on-course. You need not worry too much about timing as you will most likely get the maximum penalty anyway. It is a good idea, however, to try to correct your odometer. Simply record your mileage when you turn around and when you regain the course. Double this distance and add it to each official mileage until you next zero your odometer.

How do you know that you are lost? Here are some hints:

1. You get to an intersection for which no MRD or route instruction is applicable.

2. You pass the mileage attached to an instruction without being able to execute the instruction.

3. You drive beyond a call-back mileage (if specified).

The last hint refers to maximum distances between instructions or checkpoints specified on leg data slips or in the rally's general instructions. Not all rallies provide call-back mileages.

Do not get too discouraged when you get lost. Most novice teams get lost at some point in the rally.

3. Speeds & Timing

So far, we have only explained how to follow the rally route. To get good scores you also need to drive at the correct speeds. Speeds are usually specified in the route instructions with the CAS instruction (commence/continue/change average speed), but may also be specified on leg data slips and occasionally in the rally's general regulations. A CAS instruction simply tells you to start driving at a new speed. Another common timing instruction is Pause. A Pause instruction tells you to stop for a specified amount of time. For example,

33. CAS 35 at red mailbox.

[This means that you should Change Average Speed to 35 when you pass a red mailbox.]

34. Pause 0.5 minutes at each ``No Parking'' in the next 1.0 miles.

[This means that you should stop 30 seconds at each no parking sign in the next mile. There may be zero, one, or more such signs.]

The most important part of rallying, however, is staying on course. Points add up very rapidly if you fail to follow the course-directing instructions properly.

Rallyists generally rely on some sort of equipment to help them maintain the correct speed. This equipment may range from calculators (single memory, non-programmable), tables showing the times it takes to travel distances at different speeds, a rally wheel (basically a circular slide rule designed for rallying), odometers that can measure to accuracies of .01 miles, and rally computers. Novice rallyists are most likely to use one of the first two methods, or simply run seat-of-pants (no equipment). In any event a good rule of thumb is to drive at the designated speed + 10% to compensate for stopping, turning, etc.

4. Controls

Controls are locations where your arrival is timed and your score for a leg is calculated. There are two basic types of controls: open controls, or checkpoints; and Do-It-Yourself controls.

4.1 Open controls (checkpoints)

At unidentified points in the rally you will reach a timing control, known as a checkpoint or open control. These controls, along with Do-it-Yourself-Leg controls described later, determine your score for the rally. Your score at an open control is the difference between the time it took you to reach the control and the time it should have taken you if you drove at precisely the specified speeds and stayed on course. A rallyist is penalized 1 point for each .01 minutes early or late, up to some maximum which varies, but is usually around 300-500 points (3-5 minutes). The goal is to get the lowest score.

An open control is identified by a sign with the symbols for a check and a point (check-point, get it?). Just beyond such a sign a car will be parked on the shoulder of the road, most likely facing you. You should drive past this car, pull onto the shoulder of the road, and walk back to the checkpoint car with your scoresheet. You must not block the road at the checkpoint sign as other cars will be entering the checkpoint. At the control car a member of the checkpoint crew will write your arrival time and assigned departure time on your scoresheet. The departure time is the time you should leave this checkpoint, starting the next leg of the rally. An departure time is usually your arrival time rounded to an even minute, plus four or five minutes. This departure time is used by the next checkpoint to calculate your transit time for that leg. For proper scoring, you must wait at the checkpoint until your assigned departure time and prepare for the next leg.

Some rallies specify in their general instructions that legs are timed from an outmarker to the next control. For these controls, the given departure time is the time you should leave the outmarker; you should proceed to the outmarker and wait for your departure time there. Again, do not block the outmarker; pull over either a short distance before or after it.

In addition to writing your departure time on your scoresheet, the checkpoint crew will give you a leg slip. The exact format of a leg slip varies, but an example is below. You should read this slip carefully before leaving the checkpoint. Most importantly, it will tell you the next instruction to execute. This may be different than expected, as cars which fall for a trap may use extra instructions to get to the checkpoint. The checkpoint serves to get everyone back to the same point in the instructions.

Leg: 1

Leg Mileage: 16.49

Leg Time: 45.23

Next Instruction: 22

Outmarker: STOP

CAS: 30

Special Instructions: FireHouse Rd. does not exist.

Critique: A simple leg to get you started. No course following

traps, but if you took the pause in instruction #16,

you were 2 minutes late.

The above leg slip is for leg 1 of the rally. The official mileage for the leg was 16.49 miles. If the instructions were followed correctly, it should have taken 45.23 minutes to complete the leg. The next instruction to execute is number 22. The next leg begins at the next STOP sign. You should be driving 30 MPH when you leave the outmarker (the STOP sign). A special instruction indicates that FireHouse Rd. does not exist, so if you ever encounter FireHouse Rd. you should not consider it to be a road. Finally, there is a critique of the last leg indicating what the trap was.

Suppose you began the rally at 2:05 and the checkpoint crew timed you reaching the checkpoint at 2:52.03. It took you 47.03 minutes to travel the leg. This gives you a penalty of (47.03-45.23)*100, or 180 points. Since falling for the trap would cause you to be off by 2 minutes, falling for the trap but driving the correct speeds would result in a 200 point penalty. Therefore, you probably fell for the trap, but drove faster than the specified speed, causing your penalty to be slightly less than 200.

It might seem easy to get a 0 on a leg simply by going faster than the specified speed, stopping when you see the checkpoint, and waiting for the right time to cross the checkpoint. However, it is illegal to go slower than around 10 MPH in sight of a checkpoint. Breaking this rule adds a large penalty to your score (around 200 points).

4.2 Do-It-Yourself-Legs (DYL controls)

Do-It-Yourself legs (DYLs) are legs that do not end in a checkpoint. The instructions for a DYL are identical to a normal leg, except for an instruction that says ``End DYL at ...''. These legs are untimed. Instead, you simply record the distances you travel at each speed and compute how long it should take you to travel those distances. You enter this time on your scoresheet. The time is compared to the official time for the leg to get your score.

In general scores on DYLs are very low. However, DYLs may contain traps just as any other leg does. If you fall into a trap, you will travel the wrong distance and compute the wrong time, leaving you with a bad score. For DYLs, both the driver and navigator should be concentrating on staying on course. Maintaining the designated speeds is pointless.

To compute the time it takes to traverse a DYL, you must record your odometer mileage at the start and finish of the DYL, as well as at every speed change. For example, suppose the following instructions were in a DYL.

73. Begin DYL at ``STOP''. CAS 30.

74. Left at T. CAS 33.

.......

79. Right after church. CAS 35.

80. End DYL at corner of Main and Cedar.

Suppose instruction 73 is executed at mileage 73.51, instruction 74 at 77.26, instruction 79 at 85.10, and instruction 80 at 91.49. Now you need to compute the time you should have driven each speed, using the formula

finish miles - startmiles

-------------------------------- x 60

CAS

Using the above data, we get 32.70 minutes:

-----------------------------------------------------------

| CAS| End| Distance| Time (in minutes) |

-----------------------------------------------------------

| | 73.51| | |

-----------------------------------------------------------

| 30| 77.26| 3.75| 7.5 |

-----------------------------------------------------------

| 33| 85.10| 7.84 | 14.25 |

-----------------------------------------------------------

| 35| 91.49| 6.39 | 10.95 |

-----------------------------------------------------------

------------------------------------

| Total Time 32.7|

------------------------------------

| OCF .96|

------------------------------------

| Adjusted Time 34.06 |

------------------------------------

The above calculations were based upon the mileages read from your odometer, not the official odometer; you must use your odometer calibration factor, computed in the OCZ, to compensate. To do this simply divide the time computed (32.70) by your calibration factor (.96) to get the real time (34.06). This number should be entered in the Elapsed Time entry for the DYL leg on your scoresheet. NOTE: if there were any pauses during the DYL, these must be added to your elapsed time (after using your odometer calibration factor).

Rather than starting a DYL in the route instructions, many rallies will instruct you to start a DYL at an open control. This should be noted on the leg data slip. Timing for the DYL will start either at the control's timing line or outmarker, as if you were starting a normal leg.

If you are given an departure time to start a DYL, you must give yourselves an departure time at the end of the DYL. This time will be used as the start of the next leg. You compute this time by adding your computed elapsed time to the departure time at the start of the DYL. This value is the time of day when you should have arrived at the end of the DYL, if you had followed the speeds. Place this value in the Arrival Time entry for the DYL leg on your scoresheet. Then, round up this value to the next whole minute and add five minutes. If this time is in the past, you may add enough minutes to let you start on time. Place this time in the Departure Time entry for the next leg on your scoresheet. If the DYL ends the rally or ends at a the rest break, they might not give you an departure time; just enter your elapsed time.

In the previous example, assume the DYL started at a checkpoint outmarker (where your odometer read 73.51) and you were given an departure time of 4:13. At the end of the DYL you would give yourselves an departure time for the next leg of 4:13.00+34.06+5 rounded up, or 4:53.

It is important to fill out your scorecard at the end of each DYL. If you enter the next open control without having filled out your scorecard, you will get the maximum penalty for the DYL. If you did not give yourselves a departure time at the end of the DYL, when you were given an departure time to start the DYL, you may also get a max for the current leg, since there is no departure time with which to compute your transit time for the leg.

4.3 Free Zones

A free zone is a portion of a rally in which the rallymaster guarantees that there will be no checkpoints. In general, major highways are free zones. A rallymaster identifies free zones by the instructions ``Begin free zone'' and ``End free zone''. The main reason for free zones is to allow the rallyists to drive the speed limit rather than a lower rally speed on major roads, and to compensate for traffic lights. It is a good idea to drive the speed limit through a free zone; when you reach the end of the free zone, calculate how long it would take you to drive it at the specified speed. You should stop at the end of the free zone and wait for the proper amount of time to pass before continuing.

5. The End

Rallies usually end at a restaurant in the vicinity of the start. Many people stick around, rehashing the rally, while the scores are being totalled. If possible, the novice awards (free rally passes) will be given out right away. A few weeks later, each participant should receive \italic{Checkpoint}, the BRMSCC newsletter, containing the official scores and other information. Personalized trophies for the winners of each class are usually available at the next event.

6. Traps

From the description given so far, rallies sound pretty simple. There are rules to learn, and that takes a few rallies, but then what? Well, things generally aren't that simple. The goal of a rallymaster is to write instructions that contain traps. A trap is an instruction that is easily mis-interpreted. Some common traps are:

6.1 Timing Traps

Starting time traps Watch for ``Start at 2:01 plus your car number in minutes'', rather than the more common 2:00.

Transit Zones Ignore pauses and gains within the OCZ or other transit zones which give you a specified amount of time to reach the end. If you are told to take 20 minutes to reach instruction #10 and instruction #5 is ``pause 1 minute'', you still take only 20 minutes to reach instruction #10.

6.2 Course Following Traps

Spelling traps These are instructions in which words are quoted, but spelled differently than on the sign. For example, an instruction might say ``Right at Murraysville.'', and you may first encounter a sign that says ``Murrysville''. Be patient, don't turn. You should later find a sign spelled the same way as the instruction.
Protection A protection trap occurs when a stop sign is in an unexpected place, or is hard to see. For instance, a stop sign might be attached to a telephone pole, or be behind a tree. Falling into a protection trap means that the Protection MRD should have been used at the intersection, but wasn't.
Onto An onto trap is similar to a protection trap in that it indicates a failure to apply the Onto MRD. In particular, the road you are ``onto'' may turn, and you would be expected to turn to stay on the same road.
Overlap An overlap trap occurs if you fail to complete one instruction before beginning the next. Instructions most likely intended as overlap traps usually say something like ``CAS 30 for 1 mile.'' This instruction is not complete until after the 1 mile has been driven. Only then may you begin working on the next instruction.
Blackjack A blackjack trap is purely a psychological trick. It is done by putting a checkpoint within sight of a turn in the rally route. Novices especially may be tempted to go directly to the checkpoint, forgetting that an instruction or MRD requires them to turn away; or they may simply feel uneasy about turning away.

The above list is far from complete, but describes some of the more common traps. One challenge for rallymasters is to include traps that can trick even experienced rallyists.

After reading this section, it may seem that a road rally could be extremely frustrating, and at times this is true! However, good rallies are constructed to be ``fail-safe''. This means that even if you fail to stay on course, you will still reach the checkpoint. This is done by having two paths that reach the checkpoint, one correct and one the path you would take if you fell for the trap. In a fail-safed rally, you rarely realize that you have made a mistake until you reach the checkpoint and see your score. Of course, it is still possible to get lost on fail-safe rallies. You must always be alert for signs and landmarks referred to by instructions.

7. Calculating your time

It must be stressed that the most important aspect of rallying is to stay on course. However, as long as you stay on course, it is useful to know how good your timing is. A good beginning measure is to compute the expected time at each speed change (CAS). This computation is very similar to figuring the DYL times. First, note your mileage at the start of the leg. At the first speed change, note the mileage and current time. Then compute the distance and the time it should have taken you to travel that distance at the initial speed. Add the computed elapsed time to your departure time from the checkpoint. This is the time at which you should have reached the speed change. Compare this to the actual time to see if you are fast or slow. At each succeeding speed change, perform this same procedure using the mileage and computed time from the previous speed change. Here is an example:

----------------------------------------------------------------------------

| CAS| End | End | End | Your | Official | Expected | Error |

| | (sec) | (100ths)| | | Time | | |

----------------------------------------------------------------------------

| | 3:05:00| 3:05.00 | 54.36 | | | 3:05.00 | |

----------------------------------------------------------------------------

| 30| 3:22.26| 3:22.43 | 62.43 | 8.07 | 16.81 | 3:21:81 | .62 |

----------------------------------------------------------------------------

| 20| 3.22.36| 3.22.60 | 66.35 | 3.92 | 12.25 | 3:34.06 | 1.46 |

----------------------------------------------------------------------------

The equations used to do the above computations are:

CAS is the speed specified in the route instructions or on the leg slip.

End Time (seconds) is the official departure time for a leg, or the time at which you clocked yourself as switching to a new CAS.

End Time (100ths) is the same as End Time (seconds) except that the seconds are converted to .01 minutes by dividing them by 60.

End Miles is your odometer reading when changing to a new CAS.

Your Distance is the distance driven at the last speed, computed as

Distance = End Miles (this leg) - End Miles (last leg)

Official Elapsed Time is how long it should have taken you to drive the computed Distance at the given CAS, compensating for your odometer calibration.

Distance

-------- x 60

CAS

Official Elapsed Time = ----------------

OCF

Expected Time is the time that you should have begun the new speed.

Expected Time sub{n} = Expected Time sub{n-1} + Official Elapsed Time

Error is how much your End Time (.01 min) differs from the expected timing. If the subtraction results in a negative number, it means you are late. If it results in a positive number, it means you are early.

Error = Official Elapsed Time - EndTime (.01min)

This procedure is also useful for Free Zone calculations. Drive the Free Zone at a comfortable speed, computing any speed changes as above. When you reach the end of the Free Zone, stop and treat it as a speed change, computing the expected time of arrival. Hopefully, this computed time is in the future (if you are reasonably quick with the numbers it usually is). At the computed time, continue onward.

8. Example

Just to give you the flavor of a rally, here is an excerpt from the rally of April 1988.

The MRDs are:

1.Protection
2.Left at T
3.Straight as Possible

0.00 53. Begin official mileage at Stop, and turn left. CAS 30.

[This means that you should zero your odometer at a stop sign, and turn left at that intersection. Your average speed should be 30 MPH.]

0.58 54. Left on Pa. Route 981 before underpass (sign on left). Begin free zone.

[At mileage 0.58 you should go left on 981. This turn should be before an underpass. A free zone is starting; there can be no checkpoints until the instruction ``End free zone.'' Parenthetical comments are only hints. Here the hint is that the 981 sign is on your left.]

2.60 55. Left at Hope Memorial Lutheran Church.

[You should turn left at mileage 2.60. The landmark should be at the turn.]

56. Left at ``TO 70'', may be redundant.

[Turn left at a sign with the quoted words on it. ``May be redundant'' specifies that you should execute the instruction whether or not the main road goes left.]

57. Right after underpass. End free zone.

[Turn right after an underpass. The free zone is over; a checkpoint may occur at any time.]

58. Left after ``SPORTSMENS''. CAS 27. Pause 20 seconds at

each black-on-yellow diamond shaped curve arrow sign prior to the next

instruction.

[Turn left after the sign with the quoted word on it. Change your speed to 27 MPH. Stop (or reduce your speed) so that you add 20 seconds to your leg time for each sign as described.]

Between each pair of these instructions you may need to use 0 or more MRDs to stay on course.

9. Summary

We hope this has given you some idea of what rallying is like, but the only way to really understand it is to give it a try. Hope to see you at the next rally!

9.1 The Start

1. Register early and pick up the rally instructions.

2. Set your watch to the official time.

3. Read the instructions carefully and ask questions.

4. Prepare to run the Odometer Calibration Zone by driving to the start of the rally and noting your odometer reading.

9.2 The OCZ

1. Note your odometer reading at the start of the rally.

2. Follow the instructions to the end of the OCZ.

3. Note your mileage at the end of the OCZ and find a good place to pull off the road.

4. Determine when you must leave the OCZ (from the generals or instructions).

5. Compute your Odometer Calibration Factor (yours/official) and adjust all official mileages (official*OCF).

6. At the proper time, leave the OCZ, driving at the assigned speeds (+10%).

9.3 Course-Following -- at each intersection

1. If the next route instruction is referenced to a mileage and you are at that mileage, execute the instruction.

2. Determine the main road-- use the highest priority, applicable MRD.

3. If the next instruction is applicable and does not follow the main road, execute the instruction.

4. Follow the main road.

9.4 Open Controls (Checkpoints)

1. Drive beyond the checkpoint car and pull off the road.

2. Take your score card back to the checkpoint car.

3. Get your departure time and leg data slip from the crew.

4. If outmarkers are used, proceed near the outmarker and pull off the road.

5. Locate the next instruction to execute from the leg data slip.

6.Leave when your departure time arrives.

9.5 DYL Controls

1. Note your odometer reading at the start of the DYL.

2. Note your odometer reading at each speed change.

3. Note any pauses or gains specified in the route instructions.

4. At the end of the DYL, compute the elapsed time based on your odometer readings.

5. Compensate with your Odometer Calibration Factor.

6. Add any pauses and subtract any gains from the elapsed time.

7. Enter the elapsed time for the DYL on your scorecard.

8. If you were given an departure time to start the DYL, compute an departure time for the next leg and enter it on your scorecard.

Go back to the main TSD rally page.