Freahk - the approach that you suggest is not consistent with the underlying design and purpose of the passenger generation algorithm. Generated passengers are desired trips, not attempted trips. The inherent desirability of a destination is a fundamentally different thing to its reachability: the current system is specifically designed to simulate that separation, and the alternative destinations system to simulate the fact that people will choose less than ideally desirable destinations on the basis of reachability. This system was designed to replace an earlier, much cruder system using distance ranges because that system produced intractable anomalies.

Rather than use the crude proxy of distance for destination choosing in passenger generation, it is better to calibrate the parameters of the current system to work better. One thing to consider is increasing the minimum journey time, as it is in reality likely to be rare for people to be willing to make a trip outside their homes, but only if that trip can be completed in less than 10 minutes. A 12-15 minute minimum journey time may well be worth considering.

Before looking into that, however, I am in the process of re-running the above tests but with more fine grained data about tolerances to get a better idea of the distribution produced by each minimum, maximum and skew set. The result of the first of these tests, with the current Stephenson-Seimens settings unchanged (skew 5, minimum visiting journey time tolerance of 8 minutes and maximum of 5,400) is as follows:

Average tolerance: 89 minutes

Average journey time: 56 minutes

Average journey time minutes per Simutrans day: 205

Proportion of passengers with a tolerance of >10 hours: 1.9%

Proportion of passengers with a tolerance of <10 minutes: 13%

Proportion of passengers with a tolerance of <30 minutes: 40%

Proportion of passengers with a tolerance of <1 hour: 53%

Proportion of passengers with a tolerance of <3 hours: 68%

This shows a very high proportion of trips (32%) with a tolerance of >3 hours, which does suggest that a skew of 5 leads to excessive journey time tolerances overall.

**Edit 1**: Running the same test again, with skew at 6 instead of 5, we get the following:

Average tolerance: 31 minutes

Average journey time: 37 minutes

Average journey time minutes per Simutrans day: 147

Proportion of passengers with a tolerance of >10 hours: 0.02%

Proportion of passengers with a tolerance of <10 minutes: 40%

Proportion of passengers with a tolerance of <30 minutes: 70%

Proportion of passengers with a tolerance of <1 hour: 75%

Proportion of passengers with a tolerance of <3 hours: 79%

**Edit 2**: The same test again, but with a skew of 7 gives the following:

Average tolerance: 23 minutes

Average journey time: 36 minutes

Average journey time minutes per Simutrans day: 135

Proportion of passengers with a tolerance of >10 hours: 0%

Proportion of passengers with a tolerance of <10 minutes: 59%

Proportion of passengers with a tolerance of <30 minutes: 78%

Proportion of passengers with a tolerance of <1 hour: 79%

Proportion of passengers with a tolerance of <3 hours: 79%

**Edit 3**:

Here is a chart of the distribution curves with the three levels of skew:

**Edit 4**: For clarity, I should note that all of these results were obtained with the system for adjusting journey time tolerance based on the passenger success rate of the origin building disabled.

**Edit 5**: Re-running the test, but with altering the minimum an maximum as well as the skew, with the minimum now being 12 minutes and the maximum now being 12,000 minutes and with a skew of 6, we get these results:

Average tolerance: 45 minutes

Average journey time: 42 minutes

Average journey time minutes per Simutrans day: 171

Proportion of passengers with a tolerance of >10 hours: 0.35%

Proportion of passengers with a tolerance of <10 minutes: 0%

Proportion of passengers with a tolerance of <30 minutes: 56%

Proportion of passengers with a tolerance of <1 hour: 70%

Proportion of passengers with a tolerance of <3 hours: 77%

**Edit 6**: The same minimum and maximum with a skew of 7 gives:

Average tolerance: 28 minutes

Average journey time: 36 minutes

Average journey time minutes per Simutrans day: 114

Proportion of passengers with a tolerance of >10 hours: 0.002%

Proportion of passengers with a tolerance of <10 minutes: 0%

Proportion of passengers with a tolerance of <30 minutes: 70%

Proportion of passengers with a tolerance of <1 hour: 78%

Proportion of passengers with a tolerance of <3 hours: 80%