Modeling simulations

Optima data model provides several tables for storing data associated to simulations.

Some tables contain input data for the simulations, othet tables are used for storing the simulation results.

If the Mid-Term Forecast engine is properly installed, results from the past day are stored every midnight by appending the suffix *_1 to:

Older result tables are shifted back one day and renamed *_2, *_3, ...*_n and so on.

You can configure the number of saved days n as needed, acting on the configuration of the MTF engine (→ MTF main configuration).

Important:  The number n must be set considering the DB space available.

Main tassonomy of simulations data

Link-to-Link turn probabilities and Lane-to-Link turn probabilities for the assignment network, are stored by day type and mode of transport (see Network model modes>MODE table).

Usually, probabilities are determined from:

  • An assignment.
  • Real data.

They are fed as input to simulations and may be associated with a specific OD pair.

Probabilities can be also extrapolated from simulation results themselves.

Values are given as weights. They can represent either absolute flows, probabilities, or percentages.

Therefore, depending on the data’s content, you may need to scale data with respect to the total weight of the turn category considerated.

Each entry refers to the entire interval that ends at the specified instant. The beginning of an interval is either:

  • The simulation start time.
  • The end of the previous interval that has matching unique attributes.

A specific set of tables are used to store different types of data provided by TRE about links.

  • RLIN_TSYS_TRE*
  • RLIN_TSYS_TRE_RLTM*
  • RLIN_TSYS_TRE_FORE*
  • RLIN_TSYS_TRE_EQUA*

RLIN_TSYS_TRE*

The tables RLIN_TSYS_TRE* store flow, speed, and state results produced by TRE.

Results are based on links and transport systems.

Some results are calculated as instant values, others as average values.

All average values are "averages over time", based on a "results time period" composed of several "simulations periods". For every simulation period is calculated a specific result and all results are used to calculate the average values.

RLIN_TSYS_TRE_n tables may be used to store results from past days.

The numeric suffix n is added to indicate the number of days before the current date.

RLIN_TSYS_TRE_RLTM*

The RLIN_TSYS_TRE_RLTM*table stores the most recent results of the simulation associated to a link.

RLIN_TSYS_TRE_FORE*

RLIN_TSYS_TRE_FORE* tables store the most accurate results of the daily simulation associated to a link.

RLIN_TSYS_TRE_FORE_n tables may be used to store results from past days.

The numeric suffix n is added to indicate the number of days before the current date.

RLIN_TSYS_TRE_EQUA*

For each interval time START TIME - END TIME, the RLIN_TSYS_TRE_EQUA table contains the results of the balanced simulation of TRE, focused on each type of modeled day.

A specific set of tables are used to store different types of data provided by TRE about turns.

  • RTUR_TSYS_TRE*
  • RTUR_TSYS_TRE_RLTM*
  • RTUR_TSYS_TRE_FORE*
  • RTUR_TSYS_TRE_EQUA*

RTUR_TSYS_TRE*

The tables RTUR_TSYS_TRE* store turn flow results produced by TRE.

Results are turn based, identified by the Link-Link or Lane-Link pairs forming the core of the unique key.

RTUR_TSYS_TRE_n tables may be used to store results from past days.

The numeric suffix n is added to indicate the number of days before the current date.

RTUR_TSYS_TRE_RLTM*

The table RTUR_TSYS_TRE_RLTM stores the turn flow results of the most recent TRE simulation only.

The structure of this table is identical to the structure of the table RTUR_TSYS_TRE.

RTUR_TSYS_TRE_FORE*

RTUR_TSYS_TRE_FORE* tables store the most accurate turn flow results of the day as they are simulated by TRE. The structure of these tables is identical to the structure of the table RTUR_TSYS_TRE.

RTUR_TSYS_TRE_FORE_n tables may be used to store results from past days.

The numeric suffix n is added to indicate the number of days before the current date.

RTUR_TSYS_TRE_EQUA*

For each interval time START TIME - END TIME, the RTUR_TSYS_TRE_EQUA table contains the results of the balanced simulation of TRE, focused on each type of modeled day.

A predefined path is an ordered sequence of links of the assignment network.

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