Customizing Intersection Volume Blocks for use with TIAH
To create a custom INTVOL Block, follow these directions:
1. Create your block and arrange it to suit your requirements. (Do not add any arrows at this stage.)
2. Although not strictly necessary, we recommend all entities be placed on layer 0. We would also recommend that you use a unique name for your Intvol block Text Style, e.g. “INTVtxt”. This means that if some user later changes the font associated with “Standard” then your blocks will still appear as you originally intended.
3. Each Intvol block MUST contain a total of 19 Attributes. The attribute TAG names must be as follows:
| # | TAG NAME | PROMPT |
| 1 | ID | Intersection ID |
| 2 | NBL | Northbound Left |
| 3 | NBT | Northbound Through |
| 4 | NBR | Northbound Right |
| 5 | SBL | Southbound Left |
| 6 | SBT | Southbound Through |
| 7 | SBR | Southbound Right |
| 8 | EBL | Eastbound Left |
| 9 | EBT | Eastbound Through |
| 10 | EBR | Eastbound Right |
| 11 | WBL | Westbound Left |
| 12 | WBT | Westbound Through |
| 13 | WBR | Westbound Right |
| 14 | NB | Northbound |
| 15 | SB | Southbound |
| 16 | EB | Eastbound |
| 17 | WB | Westbound |
| 18 | EASTWEST | East⁄West |
| 19 | NORTHSOUTH | North⁄South |
The Tag names are critical but the attribute prompts are not and can be defined as anything you like or feel comfortable with.
The attributes MUST be in the order shown above to ensure correct importing of the data.
4. To have the attributes in the correct order, use the WBLOCK command; select all the graphic entities of the Intvol block, then select each of the attributes, in turn, in the order listed above. This will ensure they are in the correct sequence. Note: when prompted for the insertion point of your Intvol block, select the centre of the intended block. In this example, the insertion point will be the small red “+” at the centre.
Select “Convert to Block” while using the Wblock command ~ this will automatically convert your drawing into a block.
5. Now you can add the arrows.
You only need to add the arrows to one quadrant of the block ~ the upper right quadrant as shown here.
“Wblock” each of the arrows in turn, using the same insertion point as you selected for the block. The naming convention for arrows is important!
Please ensure you follow the correct convention for arrow naming. ~ Each arrow must be named as follows:
Left Arrow = INTarxxxL
Right Arrow = INTarxxxR
Through Arrow = INTarxxxS
Where xxx is your arrow set name.
Place the Intvol block in the “C:\Program Files\TIAH\” directory and the Arrows in the “C:\Program Files\TIAH\ARROWS\” directory and they will be picked up automatically the next time you start TIAH.