Scenario Validation

When editing the network or public transport data, it can happen that inconsistent states result. For example, if a link is deleted that is used by a bus line, the bus route will now contain a gap and might no longer be drivable.

To check for such inconsistencies and other implausible attribute combinations, select the "Validate" tab on the right side of the screen.

There are two major sections: Validations, and Plausibility Checks.

• Validations are checks performed by Tramola that highlight issues known to cause problems in simulations.
• Plausibility Checks provide data where the user itself has to decide whether the data is plausible or not.

At the moment, only checks for the Network are available. Checks for Public Transport will be added in the next version.

Network Validation

To perform the network validation, select the "Validation" tab and click on "View…" next to the Network Validation. A new tab will open in the lower half with a loading indicator. After a few seconds, the validation results should show up.

Currently, the following checks are performed:

• Links with zero length.
• Links with zero capacity.
• Links with zero freespeed.
• Links with zero lanes.
• Links with a length shorter than the Euclidean distance between its from and to nodes.
• Links that are sources or sinks (i.e. nodes that have only incoming or outgoing links).
• If the mode-specific sub-graph of the network is disconnected, i.e. it is not possible to reach every link from any other link.

The first five checks are straightforward and can be fixed by editing the network. When clicking on one of the link Ids, the link is opened for editing in the top half.

Links that are sources or sinks are more complex to fix. For modes other than car it might be okay to have such links (e.g. for subways which run on separate tracks in each direction), but for car it is typically not desired, as it prevents agents from having activities on such links when they cannot reach them from any other link, or depart again from there.

The tables listing sources and sinks can therefore be filtered to only show warnings for specific modes by clicking on the Triangle-icon in the table header.

The section about disconnected sub-graphs shows of how many separate sub-graphs a mode-specific network is composed of. Again, for modes other than car it might be okay to have such sub-graphs (e.g. for bus-networks in two different towns without a common stop), but for car it should typically be only a single sub-graph to ensure that agents can reach any location in the network from any other location.

Network Plausibility Checks

To perform the plausibility checks for the network, select the "Validation" tab and click on "View…" next to the Network Plausibility Checks. A new tab will open in the lower half with a loading indicator. After a few seconds, a first table will be shown.

The plausibility checks for the network currently provide three tables, each showing the number of links for a given attribute-pairing:

• Speed vs Lanes: This shows the number of links when grouped by freespeed and number of lanes. The expectation is that links with low speeds rarely have more than 1 lane. Whereas links with high speeds (e.g. freeways) often have 2, 3, or even more lanes. By clicking on a cell, the list of links with this attribute-pairing is shown which allows to verify individual findings.
• Speed on Succeeding Links: This shows the number of links when grouped by freespeed and the freespeed of the links that succeed it. The expectation is that the speed-difference between two succeeding links is rather small. It is uncommon that a freeway with 130km/h directly leads into a residential road with 20km/h. Thus, the cells are color-coded to show what we consider outliers that should be verified if they are correct, or if a data-error occurred. Clicking on a cell opens a list of the link-pairs so they can be verified and edited if necessary.
• Speed on Opposing Links: This is similar to the speed on succeeding links, but shows the difference between a link and the link in the opposite direction. The assumption is, that both directions of a road usually have the same speed signaled.