Control Zone Rally

This iPhone app is designed for a particular type of automobile rally called a Control Zone Rally. In a Control Zone Rally you are given some combination of time, speed, and distance required to traverse a course from a defined starting point to a finish line. Your starting time will also be assigned as some minute or half minute after the hour in which the race begins.

Set these conditions by touching the "Setup" button to access a screen where the starting time, course time, course speed, or course distance can be entered. When you've set these conditions, touch the "New Rally or Leg" button in the upper right hand corner of the screen to return to the main screen where a map and your progress will be recorded.

The Start Now! button allows starting a new rally or a leg of a rally with a single click. This allows you to preset time, speed, and distance for the upcoming leg, and to touch the button exactly when the new leg begins. In other words, with the Start Now! feature, the user doesn't wait until the clock ticks down to a defined starting minute or minute and a half.

GPS inputs trace the path along the rally route. Measurements of actual versus ideal time and distance will be shown in seconds ahead or behind schedule. From time to time you may also record time and distance covered an the error against the ideal course time and distance by touching the Add Split button. As an option you can select the frequency of splits automatically every quarter, half, or full minute.

Options include subtraction of distance when you travel off course. A toggle button switches between on course (blue line) and off course (red line) travel. Time splits can be set for automatic error checks. Also, map type can be set to standard, satellite, or hybrid.

You may fine-tune the app's distance and clock figures to the rally's official measures with the options in the Adjust popup. Unlock to make adjustments and lock to save the changes you make and to prevent inadvertent changes.

Distance measurement can be set to miles or kilometers and time measurement can be set to minutes and seconds or decimal minutes. Make your selections in the app preferences in the iPhone's System Preferences.

An adjustment factor between 0.800 and 1.200 can be used to synchronize distance measured by GPS to rally distance. This adjustment applies to all distance measurements shown after the adjustment has been selected.

If the app's Time of Day (T.O.D.) clock shown at the bottom of the map view does not match the rally's official clock, you may synchronize the two clocks by making small adjustments as required.

For better GPS reception and improved accuracy while racing, third-party wireless GPS receivers are recommended. This app has been tested with Bluetooth connectivity to a Dual XGPS150A Universal GPS Receiver.

A heads-up display for the Driver shows the time error, the time remaining for the course, the distance error, and the average speed for the course.

Disclaimer: Continued use of GPS running in the background can dramatically decrease battery life.


change in version 6.0
  • Added estimate of distance travelled between GPS distance signals. This improves the accuracy of the distance measurement and importantly reduces the rapid changes in time and distance error computations and displays to make it easier to maintain a desired pace
change in version 5.2
  • Numerous GUI enhancements and a few bug fixes
change in version 5.1
  • Corrected display of clock measuring in decimal time or "cents" to include leading zeros when hours or minutes are single digit whole numbers.
changes in version 5.0
  • Redesign of GUI and some functionality for better readability and use
  • On main display, the distance and time errors relative to ideals are displayed in the same relationship as they are shown in the split table. Formerly, the time error and average speed were displayed
  • On the Driver's heads-up display, the distance and time errors are displayed along with the average speed and the time remaining on the rally or leg
  • The background and displayed numbers in the table of splits and errors has been changed to allow for better viewing both day and night. Likewise, the Driver's heads-up display had been changed for better readability
  • From the main display, you may either Stop processing to reset starting conditions for a new rally or leg, or you may Pause the current computations for any reason including the common situation of logging time and errors at a checkpoint. When paused some of the display will change color to orange
  • When the Setup is selected, the next full minute will be set on the Start slider. Text above the slider will indicate whether the start time you chose is within the current or the next hour
  • Minimum and maximum settings for Time, Speed, and Distance are displayed beneath the respective sliders and new, improved error testing has been added to prevent erroneous or illogical settings from being introduced
changes in version 4.3
  • Added option to adjust Time of Day (T.O.D.) clock to match official rally clock, if necessary
  • Adjustments, if any, to odometer or clock are shown in the right-hand corner of the lower toolbar
  • Table of splits is wider and has a larger font for better readability
changes in version 4.2
  • Location access is now always available by default even when the app is in background mode thereby improving distance measurements and route tracking. In some cases, you may have to be sure that "Always" is checked in "Settings" for this app
  • Some formatting adjustments due to iOS 10
  • GPS Info button only shows when Dual GPS receiver is connected

revised: April 16, 2017