Here we find additional data concerning routable highways ,such as its length ,its direction (if one way),the maximum speed allowed,and its house address information if any.
The subfile looks like this:
NET Offset | NET Header |
00 | Header Length |
02 | GARMIN NET |
15 | Pointer to beginning of NET1 |
19 | Length of this block |
1D | Road definitions offset multiplier ( power of 2) |
1E | NET2 Segmented Roads |
22 | Length of this block |
26 | offset multiplier ( power of 2) |
27 | NET3 Sorted Roads |
2B | Length of this block |
2F | Sorted roads record size |
NET1
The following table shows a ‘typical’ road definition entry in NET1 ; the length of each record varies depending on:
More information and examples in Exploring IMG
Items | Bytes | example |
labels | 3 per label | 12 00 00 ,45 00 00,24 01 81 |
Road Data | 1 | &44 |
Road Length | 3 | 32 01 = &h132*2 metres |
RGN_index_overview | 1 per record | 1,81 ( ie 2 records) |
Highway pointer | 1 | 01 05 ,01 06 |
Subdivision number | 2 | |
House_number blocks | 1 | Set if bit 4 or Road Data is set |
Street Address info block | varies | |
NOD length of pointer | 1 | 1 or 2 |
NOD2 offset | 2 or 3 | See Exploring IMG |
| (©) Pinns UK |