Author Topic: Using Adventure Cycling GPS Data  (Read 6080 times)

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Offline Fred Hiltz

Using Adventure Cycling GPS Data
« on: March 21, 2011, 02:16:57 pm »
This topic summarizes some of the FAQ and answers that have arisen about effectively using the GPS data from Adventure Cycling.

Find more information in the GPS Data User Guide. From the ACA front page, go to Routes and Maps > GPS Information. Click the link to the GPS Data User Guide. This topic does not duplicate the Guide, but may repeat some of its information for continuity.

Most of us know the Garmin line of GPS receivers (GPSR) best. The information here nearly always applies to receivers from other manufacturers, but you should check their owner’s manuals to be sure.

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Offline Fred Hiltz

Re: Using Adventure Cycling GPS Data
« Reply #1 on: March 21, 2011, 02:18:45 pm »

When buying maps, you often have the choice of pre-loaded memory cards that fit your receiver or DVDs that install the maps on your computer (Mac or PC), where you copy some or all of the maps onto blank memory cards. Take the latter choice so you can work with the ACA waypoints and routes at home on the same maps that you will ride with. You will probably want to customize the ACA data to some degree; this is much easier when you see them overlaid on a map.

On a computer, you can also combine maps from different products into a single load for the receiver. The most common combination includes road maps for navigation and topographic maps for elevation and occasional hiking.


Offline Fred Hiltz

Re: Using Adventure Cycling GPS Data
« Reply #2 on: March 21, 2011, 02:20:18 pm »
Considerations for Long Rides

Maps: Most modern mapping receivers have enough memory to hold all the maps for a cross-continental ride on a removable memory card. However, some maps come in large chunks that may not fit. Consider loading up two memory cards and swapping mid-way.

Waypoints and routes: Most receivers cannot hold the 2000 to 3000 waypoints needed for a transcontinental ride. Swapping memory cards does not work for most, which hold routes and waypoints in a separate non-removable memory.

Create several files, allowing plenty of overlap, and reload the receiver along the way. One or two reloads should suffice. If you will not be carrying a computer or a PDA, you can put the files on a CD or a memory stick (flash drive) along with a small program like G7ToWin, which runs directly from your device without installation on a Windows computer. Beg a few minutes on a computer from a friendly local cyclist, a bike shop, or a computer shop. Most libraries will not let you connect your own devices for security reasons, probably a good policy. Do not forget to carry a short USB cable.

Power: Receivers with removable, rechargeable batteries are popular for long rides. Most use two AA cells, which run for about 12 hours. Some riders advocate one spare set and a solar charger. Some prefer to carry eight rechargeable cells and a small mains charger, needing a power outlet once a week or so and claiming less cost, less weight, and better reliability.

You can also buy single-use AA cells as you go, at somewhat higher expense and the need to dispose of them. Alkaline AA cells are good for about 12 hours in most receivers, while lithium cells last longer.

Most states in the U.S. follow the United States Resource Conservation and Recovery Act, which classifies the common alkaline, NiMH, and lithium batteries as non-hazardous waste. They can go into regular trash. However, California considers all batteries of any type to be hazardous waste, which must be taken to a recycling center, a household hazardous waste disposal facility, or a universal waste handler. Find out about other states and countries with an Internet search.

« Last Edit: March 21, 2011, 02:24:32 pm by Fred Hiltz »

Offline Fred Hiltz

Re: Using Adventure Cycling GPS Data
« Reply #3 on: March 21, 2011, 02:23:46 pm »
Considerations for Mapping Receivers

The Adventure Cycling waypoints are positioned for straight-line point-to-point navigation with a basic (non-mapping) receiver. An advanced mapping receiver can be set to work that way, or you can use its automatic routing and turn-by-turn navigation, which will require some adjustment of the waypoints.

Many waypoints just before and after an intersection are there to make sure the pointer in a basic GPSR will point the right way for the turn. Many others serve to keep the straight-line route reasonably close to a winding road. You may remove these, as your mapping GPSR will follow the road on its own.

However, do not remove too may waypoints. Leave enough to direct the auto-routing computer in the GPSR along the correct roads. Without them, the receiver will usually choose the roads that are faster or better for automobiles. The more “attractive” a nearby highway is, the more waypoints you will need to keep the unit on a local road. When in doubt, use plenty of waypoints.

Divided highways: The given waypoints do not distinguish the two directions of a divided highway. This is OK for straight-line navigation, but you must move them to the proper side of the highway for your direction of travel. Otherwise, your GPSR will send you down the highway to the next exit for a U-turn.

Variations among maps: The ACA waypoints were positioned on several different maps. You will find them close, but not exactly at, the intersection, turn, or point of interest on your own map. The difference is often a few tens of feet and occasionally a few hundreds. This is not a problem for straight-line navigation, but can lead to bizarre results when your auto-routing function leads you to a waypoint that is closer on your map to a nearby road than the road you want.

To use auto-routing, then, you will need to adjust many of the waypoints to your map and your direction of travel. This is quick and easy in Garmin’s MapSource program, which snaps a waypoint to an intersection when you move it close. Other graphical GPS data programs probably have a similar function.

Auto-routing will not follow when the cycling route leaves the roads for bike paths and trails. Switch to straight-line navigation for these segments.

Many riders prefer the simplicity of straight-line navigation throughout. The mapping receiver still shows your position on the map. The straight-line distance to the next turn is a little less than the road distance, but close enough to see from the GPSR when the next turn should appear. Except for that, all the navigation functions are the same in straight-line and road-following navigation.