import type { TransportationCategory } from "../types/transportation";
/**
 * Calculate CO2 emissions for transportation
 * @param mode - Transportation mode (car, bus, train, etc.)
 * @param km - Distance in kilometers
 * @returns CO2 emissions in kg
 */
export declare function co2PerKm(mode: keyof TransportationCategory, km: number): number;
/**
 * Get data source for a specific transportation mode
 * @param mode - Transportation mode
 * @returns Data source reference
 */
export declare function dataSource(mode: keyof TransportationCategory): string;
/**
 * Get all available transportation modes
 * @returns Array of transportation mode names
 */
export declare function getTransportationModes(): string[];