HR2009-11 Traps on every sides!? in walking mode of PND

Trigger of the research


Car navigation mode (set in the car)	Car navigation mode (set in the car)

Among the types of car navigation systems, there is small, simplified and removable car navigation system called PND (Portable Navigation Device). Other than car navigation mode, PND has a function called walking mode.

By using this walking mode, you can make it to navigate you to the destination by walking. I also am a PND user, which also carries this function (walking mode). I have used this walking mode for the first time when I've traveled to Fukushima prefecture last month.

However, when I tried to use it, although I was able to reach to the destination, I felt it was difficult to walk with the system guiding me the route. Since I had been using it as a car navigation system with comfort, it really was unexpected.

To find out the cause, I decide to ask and observe other people using the system in walking mode.

The scene when use the walking mode

To begin with, in what kind of situation do we use this waking mode?

As a major scene to use the mode, it is likely to be used when visiting the place (hop etc) for the first time that does not have a parking spot near by or you cannot get through, and that you need to park away from the destination, and walk from there.

To set to walking mode is easy. Leave the destination as it is, and just change the mode from car navigation to walking.

Study method

(1) Participants

I have asked 4 staff members for their cooperation on this test. All 4 have never used the walking mode of the PND, and this would be their first time.

Participants	Driving experience	Frequency in use of car navigation system (Route guide)
A (male)	15yrs	Less than one time/ year
B (female)	25yrs	1 to 2 times/ year
C (female)	10yrs	2 to 3 times/ month
D (male)	15yrs	2 to 3 times/ month

(2) Task

I have prepared 3 routes (destination 1,2 and 3), and asked them to walk to those destinations in walking mode only.

As I have mentioned before, it is common to use walking mode at the unknown area. Normally, the test should be done at the distant unknown place for the participants, but because I have been busy, I have carried out the test near our office (Funabashi city), but where the staff members have never walked before.

The walking distant from starting point to the destination is: to destination 1 is 190m, to destination 2 is 120m and to the destination 3 is 180m. They are distances where you can reach to the destination in 2 to 3 minutes by walking. Incidentally, when we search route with car navigation mode, it will show different route from these ones.

Destination 1

Destination 2

Destination 3

Result of the study

(1) Time required

First of all, all 4 participants have reached to either destination. The following shows the time required for the destination.

When we look at the average hour, it has taken more than 5 minutes to destination 1 (about 190m) and destination 3 (about 180m). For destination 2, it took 4 and half minutes.

When we compare the speed between participants, we can see that there is 2 to 3 minutes difference.

(2) Participants' action and behavior

I have gathered up the action and behavior of participants, which we have observed by the scene.

The place where participants often got flustered or made mistake was near the turning point. I have not actually counted, but the following 2 are what I have seen the most in their behavior and action:

"Try to coordinate the screen (map) to the direction of the road"
"Stop. Find themselves at a loss of own location in the screen (map)"

Unexpected issue here is, "Hesitate when return to the starting point (parking lot)", which is #5.

I have noticed this when returning to the office with the participant following the completion of the test.

From this table below, we see that participants start to get confused from the beginning when they have started the walking mode, and in different scenes such as on the way to the destination or when returning from the destination to the starting point.

Different traps of GPS appear on walking mode!?

When using the walking mode, various strange things, uneasy things and inconvenient things have been a taking place on the screen. By observing, it seems like the participants have been trapped.

Well, let me show you what kind of traps have been generated.

Trap 1) The mark of present location appear on different place from the actual spot, or moves around on its own.

Participant C:

Because the starting point changed, it made me start walking in different direction.
The doll in the screen is off the road and making a strange move. I thought I was walking on the different street.

Participant D:

Because the doll in the screen kept moving around, it made me feel uncomfortable all along, wondering where I was directed to. It made me frustrated. It is difficult to use when the present location moves even I am in still.

Comment by the writer:

Although different location correction functions work when it is in car navigation mode to indicate the present location in high accuracy, it seems those function do not work in walking mode.

Trap 2) The audio assist does not match to the route guide

Participant A:

Because the map matched to the landscape, I followed the map instead of the audio assist.

Participant B:

I returned for about 10m, and walked again because the audio assist guided me to turn left even the map showed to turn right. I got lost when I got careless.

Comment by the writer:

When there are multiple turnings near by (within 20 to 25m), the audio assist may go off the track.

Trap 3) Not many land marks (name of buildings, stores etc) in the map.

Participant A:

I had to make the surrounding buildings adequate to the map. It seemed that there were not many buildings. I wish to see the name of the buildings, if they have.

Participant C:

No land mark, which makes it difficult to know which direction I should walk from the start.

Comment by the writer:

The tendency got greater in residential area.

Trap 4) It shows the narrow street which makes me want to question whether I can go through.

Participant A:

I wanted to walk a little way and scout whether it was correct before I started.

Participant C:

Because a person is standing in the narrow street, I have a feeling that the person may get mad at me if I walk through. If the street is in between wall of garden, then I can go through even it is narrow, but I prefer not to walk in between walls of houses.

Participant D:

I prefer it to direct me to more easy-to-follow street rather than a short cut. When we give direction to people, we usually do not direct passage way to them. We would direct the convincingly street such as turn to the traffic.

Trap 5) When return to the parking lot, the line of the route where it directs me is gone.

Participant A:

I become more anxious when I get lost by walking than by driving, so I feel secure if I know my own track.

Participant B:

I don't know how to return to the starting point. I had to return by searching my memory.

Participant D:

Because the streets were all similar, I was not certain whether I could return on the first attempt. I did not notice the flag on the starting point.

Comment by the writer:

The screen shows a green flag on the street, but only one out of 4 participants have noticed the flag.
When you go too far from the starting point, the flag will run off the edge of the screen, and it will appear again when you change the size or scroll the map.

Participants have walked to the destination by wrestling against these traps.

Since car navigation system displays the present location by catching the GPS signal, the location accuracy will decrease at any cost in a place where it is difficult to receive.

We have seen it goes to a wrong road or the change in present location with a car navigation system of a decade ago, but it is happening the same thing in the walking mode (trap 1).

What interest me is that although the participants are car navigation system users who should know enough about the characteristic of GPS, they surprisingly get lost when they walk with the system in walking mode.

The traps that may occur only in walking mode are 4 and 5. For the case of trap 4, the car navigation system only navigates the road that is passable, but in walking mode, it seems that the system will direct the street in prior if it is passable for a person.

However, we do not expect the system to show such a narrow street. If we test this in a dark, the participants may be too afraid to walk.

Trap 5 has generated when participants return from the destination to the starting point (parking lot). Since the participants have walked by staring at the screen, when participants cannot find the green flag of starting point (screen), they have needed to return to the parking lot by searching their memory.

When you drive to the destination, you do not need to return to the parking lot, but if you use the walking mode, this will be a problem.

Some things they have done

Well, I have asked to those participants who have slipped through those traps, how they have dealt with them on the way.

Participant	How they have dealt with them on the way in walking mode
A	Decide the traveling direction by shifting the map to check the name of buildings.
B	Change the way to hold the PND in condunction of own direction.
	Don' do unnecessary thinking while walking, such as, this street may be wrong because it is narrow.
	Pass the corner to check if the corner is right to turn. (Check if it slips from the point on the map)
	Pinpoint the current location by identify address of the site (block number) and the block number on the map.
	Do not trust only the audio assit. The position of the doll on the map seems pretty accurate. Trust the map and the position of the doll.
C	When with car navigation, I can trust and go to as it directs, but with walking mode, I have to understand the map myself or I will get lost, so I've kept looking at the map all the while.
C	If I am unable to make decision, I should start walking and check which direction the doll moves.
D	Because the buildings are impossible to identify, I change the scale. Fix it to true bearings
D	Because the position of the doll mark moves on its own, I 've walked by comparing the map and the scenery

To decide the traveling direction, they compare the map and the scenery. Furthermore, when they are lost, they have doubled back, or walked the surrounding area to check.

By looking at just this, it looks like as if they are reading a map to climb a mountain.

Impression

By using walking mode, it can be convenient to reach to the destination at last. However, if you use it with the same sense when use the car navigation, you will find yourself trapped in unexpected pitfalls. If location accuracy is higher, then the trap 1 and 2 will be gone, but on the condition that it is GPS receiver, we will not have that chance.

Primarily, it is necessary to figure out the information on current location, direction and the destination. If you miss one of those 3, you will get lost. You may get lost while walking because the fact that information may be inaccurate or missing in walking mode. I thought this could be attributed to that fundamental part.

It the mode is in car navigation, the accurate position will appear, and with the feeling of security that the car is your home, and that the come back is quick, you just have less chance to become worried.

I got the impression that the guide to the destination was friendly, but not when returning. There may be different use scene of walking mode, but there should be more than a little task where you need to return from the destination to the parking lot, therefore, I wish the system will either leave the route the user has walked, or have it make easy to search again.

I also received a comment that the user felt embarrassed being heard the audio assist to other people while walking. In this time, you don't want be looked suspicious by other people. In fact, we did notice a little of people around us during the test. If the system displays the information on the screen by giving the cue in vibration instead of audio assist, the user may not be so concerned about other people.

I personally like the PND, which is portable. Although the walking mode is only bells and whistles of car navigation, I wish the product would keep reflecting the walkers’ way of use and their feeling.