AutoJ update

 Dear AutoJ Users 

A new version of AutoJ, AutoJ 2408, is now available.

The improvements are:

1. The program has been streamlined by removing all the duplicate or superfluous information.
2. The program is less complex and more relevant.
3. AutoJ now indicates the actual green time of each stage, rather than the total time of the combined stages, making it easier for the user to check timings.
4. The left turn flash g/c will be shown only if there is both a left turn lane and an “outside” right turn flash.
5. The problem of very low volumes with low capacity requiring a long green time because of the high V/C ratio has been eliminated. Very low volumes will no longer affect the green time allocation, thus improving the Level of Service of busier movements.
6. If left or right turning auxiliary lanes are too short to accommodate all the turners, the overflow vehicles are now added to the adjacent lane flow. This will mean more green time is given to the adjacent lane. Some of the earlier AutoJ versions did not have this feature.
7. Critical gap acceptance periods have been revised. The old method of adding 100 veh/hr to capacity (to allow for inter-green turns) and then reducing gap acceptance accordingly has been removed. 
8. Turns on inter-green are now calculated and subtracted from right turn volumes for signal timing purposes.
9. Earlier versions of AutoJ were found to slightly overestimate the number of vehicles taking gaps. This has been corrected.
10. Flashing green right turning time has been increased to compensate for those turners who choose to wait for a flash rather than taking gaps. 
11. A difference is now made in the gap acceptance of vehicles turning right at speed (e.g. from a main road turning right) and turning right from a stopped position. Previously these were the same.
12. Critical gaps for roundabouts have been confirmed based on the latest Roundabout Research done for SANRAL.
13. If turning right in gaps is not permitted, the way of calculating right turn flash lengths has been improved.
14. A deceleration and acceleration delay based on the g/c ratio has been added to uniform traffic signal delay. In older versions of AutoJ only priority intersections included this delay and in newer versions it was not based on g/c.
15. Pedestrian crossing directions are clarified.
16. An additional second has been added to minimum pedestrian crossing times.
17. Quarter hour volume graphs are done for each movement rather than totals.
18. The User Manual has been updated accordingly.

While there may seem to be a lot of changes, they are refinements rather than corrections. The major change users will notice is the clearer and less cluttered analysis and summary sheets.

Dr John Sampson

August 2024