---
name: travel-cost-comparison
description: Compare user-supplied fuel, EV charging, commute, and ticket costs with Everyday MCP. Use when evaluating travel options over one explicit trip count or time period.
compatibility: Requires an Everyday MCP remote connection at https://everyday.alfie.family/mcp
---

# Travel Cost Comparison

Compare options only after putting them on the same scope, currency, and trip basis.

## Define the comparison

Ask for the route distance, whether it is one-way or round-trip, number of trips or commute days, prices, efficiency, fees, traveller count, and currency.

- Use only prices, fares, taxes, parking fees, efficiencies, and exchange rates supplied by the user.
- Do not guess real-time fuel, electricity, toll, parking, transit, or ticket prices.
- Keep currencies separate unless the user supplies an exchange rate and effective date.
- Keep US gallons, Imperial gallons, `US_mpg`, and `Imperial_mpg` distinct.
- Make the time period and included costs the same before ranking options.

## Select the calculator

Use `everyday_calculate` action `catalog`, then `describe`, when the current input schema is not already available.

- `travel.fuel_cost`: total trip fuel, parking, traveller split, and fuel cost.
- `travel.ev_charge`: battery energy, wall energy, constant-power time, and electricity cost for a stated state-of-charge change.
- `travel.commute_compare`: compare caller-supplied per-distance, per-trip, and fixed costs over one commute period.
- `travel.ticket_plan`: find the least-cost combination of ticket products for a supplied journey count.

Use only the calculators needed for the user's decision.

## Make inputs comparable

For driving comparisons, supply total distance and the matching efficiency convention. A fuel price per US gallon must use `US_gal`; a price per Imperial gallon must use `Imperial_gal`.

For an EV charge, state why the selected state-of-charge change represents the compared trip or period. Treat charger power as constant only within the calculator's stated assumption.

For `travel.commute_compare`, pass already comparable user-supplied costs:

- Apply each mode to the same `commuteDays` and `tripsPerDay`.
- Use one currency for all modes.
- Include fixed costs once and per-trip costs once per trip.
- If another calculator produced a per-trip cost, copy its returned money string into the matching mode input.

For `travel.ticket_plan`, convert validity rules into usable `coveredJourneys` only after the user confirms that each product is eligible during the comparison period. State validity, zone, rider, transfer, and expiry assumptions explicitly. The calculator does not infer local fare rules.

## Present the comparison

Report each option's `values`, relevant `units`, and `assumptions`. Identify the lowest modeled cost only for the agreed scope. List excluded costs and avoid implying that modeled cost is a live quote.

## Examples

Read [references/examples.json](references/examples.json) for complete comparable-trip and ticket-plan calls. The example costs are user-provided fixtures rather than current market prices.