# Main fleet, priority and occupancy scenarios

The six main scenarios use the current arrival source, including imported truck CSVs and generated arrivals. They are available directly in Settings; the priority and bay-occupancy demonstration buttons remain separate optional worked examples. Click **Main priority + occupancy scenarios** to restore these cases without replacing the arrival data.

1. FIFO, immediate release after charging.
2. Lowest arrival SOC first, immediate release.
3. Risk + ageing, immediate release.
4. Firm minimum bay / break time of 45 minutes from connection.
5. An additional 60 minutes of post-charge idle time, held in full.
6. The same idle allowance, but the finished truck yields when a waiting truck needs its bay.

All times and vehicle classes are illustrative study assumptions and can be edited. A firm 45-minute minimum adds no delay if charging already takes longer than 45 minutes. These controls do not implement or verify driver-hours regulations.

## Fleet variation

Mixed-fleet generation is enabled by default for synthetic arrivals and converted traffic counts. Edit each class's share, usable battery capacity, vehicle DC acceptance and arrival SOC. The common target SOC applies to every generated class. Shares must add to 100%. Class shares are probabilities, not exact truck counts. A seeded independent class draw preserves the original arrival times and repeats the same fleet sample across scenarios and repeated runs. Independent replications draw different fleets and arrivals.

Turn the mixed fleet off to use the common vehicle values. CSV imports bypass the generator and retain their own battery, SOC and power values. Common fields that are unused for the selected source are disabled.

Required battery energy is **capacity × (target SOC − arrival SOC)**. For example, charging from 20% to 80% needs 180 kWh for a 300 kWh battery, or 540 kWh for a 900 kWh battery. Vehicle DC acceptance, charger rating and shared site power all constrain actual charging time. Battery percentage alone is not an energy/range comparison between different battery sizes.

## Explicit scenario overrides

Expand **Vehicle & occupancy rules** inside any scenario. Set the firm minimum, post-charge idle allowance and release rule. Optional battery and vehicle-power overrides replace every truck's values in that scenario, keeping arrival times and SOC fractions unchanged. This is a separate vehicle-design experiment, so it changes required energy. Leave a field blank to inherit its truck/common value. Explicit scenario settings take precedence over CSV values.

The main presets deliberately set explicit occupancy rules. Changing a common dwell setting therefore does not change a preset's explicit value; edit the relevant scenario instead. Capacity and priority presets remain available. Up to 20 scenarios can be compared.

## Occupancy semantics

Charging is never interrupted. A firm break is measured from charger connection and cannot be shortened by queue pressure. The baseline departure time is the later of charging completion plus post-charge allowance, and connection plus the firm minimum.

With optional yielding enabled, a finished truck may leave earlier only after the firm minimum has elapsed and another waiting truck needs its bay. Any free bay is used first, and only enough eligible idle bays are released to serve the waiting demand. If nobody needs the bay, the truck stays for the configured allowance. Yielding assumes the driver is available to move; use a firm minimum or full hold when that assumption is inappropriate. A held, energy-complete truck draws zero charging power but still occupies a bay.

Example: charging finishes at minute 10 and idle allowance is 60 minutes. Without demand, departure is minute 70. If a truck arrives at minute 20 and all bays are occupied, optional yielding releases the first truck at minute 20. With a firm 45-minute break from connection at minute 0, release cannot occur before minute 45.

CSV supports min_bay_min, post_charge_min and release_when_queued (true/false) per truck. Live / approach hub defaults support the same rules; holding snapshots can include release_when_queued and min_remaining_bay_min to preserve an unfinished firm break. An omitted holding rule is treated as a firm hold.

## Results

Results and exports retain battery capacity, vehicle DC limit, required energy, charging completion, actual bay release and release reason. Planned release is the nominal full allowance; actual release may be earlier under optional yielding. Replay and queue assessment use the actual bay state. Queue forecasts do not use future simulated diversions or early releases as known information.

Compare queue backlog and energy served alongside mean wait: a policy serving a different group of trucks can have a lower observed mean while others remain queued at the study cutoff. Software tests verify the mechanics, not the realism of the assumed fleet mix, driver behaviour or charging curve.