RouteLeg Model

Overview

The RouteLeg model represents a single segment of a route. A complete route consists of one or more legs in sequence.

Type Definition

interface RouteLeg {
  mode: 'bus' | 'local' | 'walk';
  submode?: 'driving' | 'walking';
  route_id?: string;
  trip_id?: string;
  from: string;
  to: string;
  departure?: string;
  arrival?: string;
  durationMin?: number;
  distanceMeters?: number;
  cost?: number;
  source?: 'graph' | 'distance_matrix';
}

Source: /home/daytona/workspace/source/MND-backend/src/core/types.ts:71-84

Fields

mode

string

required

Primary transport mode for this leg.

Show Values

bus: University bus servicelocal: Local transport (CNG auto-rickshaw, rickshaw, or taxi)walk: Pedestrian walking

submode

string

Specific mode within local transport (only when mode: 'local').

Show Values

driving: CNG auto-rickshaw or taxi (motorized)walking: On foot (for short distances within local mode)

route_id

string

Bus route identifier (only when mode: 'bus').Examples: bus1, bus2, bus3, etc.

trip_id

string

Specific bus trip identifier (only when mode: 'bus').Format: {route_id}_{departure_time}Examples: bus1_0825, bus3_1710

from

string

required

Origin node ID for this leg.Example: TILAGOR, CAMPUS, SUBIDBAZAR

string

required

Destination node ID for this leg.Example: CAMPUS, AMBARKHANA, MEDICAL

departure

string

Departure time in HH:MM format (only for bus legs).Example: 08:30, 17:15

arrival

string

Arrival time in HH:MM format (only for bus legs).Example: 09:20, 17:45

durationMin

number

Duration of this leg in minutes.

For buses: Time between departure and arrival
For local transport: Estimated travel time
For walking: Estimated walking time

distanceMeters

number

Distance traveled in meters.Only available when Distance Matrix API is used. May be omitted for graph-based calculations.

cost

number

Cost in local currency (Bangladeshi Taka).

Bus: 0 (free university service)
Local transport: 15-50 BDT
Walking: 0

source

string

Data source for this leg’s calculations.

Show Values

graph: Pre-computed data from graph edgesdistance_matrix: Real-time data from Google Distance Matrix API

Leg Types

Bus Leg

Represents a bus ride between stops.

{
  "mode": "bus",
  "route_id": "bus1",
  "trip_id": "bus1_0930",
  "from": "TILAGOR",
  "to": "CAMPUS",
  "departure": "09:30",
  "arrival": "10:20",
  "durationMin": 50,
  "cost": 0,
  "source": "graph"
}

Required Fields:

mode: 'bus'
route_id
trip_id
from
to
departure
arrival
durationMin
cost: 0

Local Transport Leg

Represents travel by CNG, rickshaw, or taxi.

{
  "mode": "local",
  "submode": "driving",
  "from": "AMBARKHANA",
  "to": "CHOWHATTA",
  "durationMin": 6,
  "distanceMeters": 1200,
  "cost": 25,
  "source": "graph"
}

Required Fields:

mode: 'local'
from
to
durationMin
cost

Optional Fields:

submode: Usually 'driving'
distanceMeters: If available from Distance Matrix

Walking Leg

Represents pedestrian walking.

{
  "mode": "walk",
  "from": "RIKABI_BAZAR",
  "to": "CHOWHATTA",
  "durationMin": 6,
  "cost": 0,
  "source": "graph"
}

Required Fields:

mode: 'walk'
from
to
durationMin
cost: 0

Field Relationships

Mode-Specific Fields

Field	bus	local	walk
route_id	Required	-	-
trip_id	Required	-	-
departure	Required	-	-
arrival	Required	-	-
submode	-	Optional	-
durationMin	Required	Required	Required
distanceMeters	-	Optional	Optional
cost	0	>0	0

Source Field

graph: Data from pre-computed graph edges

{
  "mode": "local",
  "from": "SUBIDBAZAR",
  "to": "RIKABI_BAZAR",
  "durationMin": 5,
  "cost": 20,
  "source": "graph"
}

distance_matrix: Real-time data from Google API

{
  "mode": "local",
  "submode": "driving",
  "from": "TILAGOR",
  "to": "MEDICAL",
  "durationMin": 15,
  "distanceMeters": 3500,
  "cost": 40,
  "source": "distance_matrix"
}

Examples

Single Bus Leg

Simplest route: one bus from start to end.

{
  "legs": [
    {
      "mode": "bus",
      "route_id": "bus1",
      "trip_id": "bus1_0825",
      "from": "TILAGOR",
      "to": "CAMPUS",
      "departure": "08:25",
      "arrival": "09:15",
      "durationMin": 50,
      "cost": 0,
      "source": "graph"
    }
  ]
}

Bus + Local Transport

Bus to intermediate point, then CNG to final destination.

{
  "legs": [
    {
      "mode": "bus",
      "route_id": "bus1",
      "trip_id": "bus1_1710",
      "from": "SUBIDBAZAR",
      "to": "AMBARKHANA",
      "departure": "17:15",
      "arrival": "17:20",
      "durationMin": 5,
      "cost": 0,
      "source": "graph"
    },
    {
      "mode": "local",
      "submode": "driving",
      "from": "AMBARKHANA",
      "to": "CHOWHATTA",
      "durationMin": 6,
      "distanceMeters": 1200,
      "cost": 25,
      "source": "graph"
    }
  ]
}

Local + Walking

CNG to nearby point, then walk to final destination.

{
  "legs": [
    {
      "mode": "local",
      "from": "SUBIDBAZAR",
      "to": "RIKABI_BAZAR",
      "durationMin": 5,
      "cost": 20,
      "source": "graph"
    },
    {
      "mode": "walk",
      "from": "RIKABI_BAZAR",
      "to": "CHOWHATTA",
      "durationMin": 6,
      "cost": 0,
      "source": "graph"
    }
  ]
}

Bus Transfer

Two buses with a transfer point.

{
  "legs": [
    {
      "mode": "bus",
      "route_id": "bus1",
      "trip_id": "bus1_0825",
      "from": "TILAGOR",
      "to": "SUBIDBAZAR",
      "departure": "08:25",
      "arrival": "08:50",
      "durationMin": 25,
      "cost": 0,
      "source": "graph"
    },
    {
      "mode": "bus",
      "route_id": "bus3",
      "trip_id": "bus3_0925",
      "from": "SUBIDBAZAR",
      "to": "CAMPUS",
      "departure": "09:25",
      "arrival": "09:50",
      "durationMin": 25,
      "cost": 0,
      "source": "graph"
    }
  ]
}

Note the 35-minute gap between legs (08:50 to 09:25) for the transfer.

Calculating Leg Duration

Bus Legs

durationMin = arrival - departure

// Example:
// departure: "08:30" (510 minutes from midnight)
// arrival: "09:20" (560 minutes from midnight)
// duration: 560 - 510 = 50 minutes

Local Transport Legs

From graph data:

// Pre-configured in edges.json
{
  "from": "SUBIDBAZAR",
  "to": "RIKABI_BAZAR",
  "mode": "local",
  "time_min": 5,
  "cost": 20
}

From Distance Matrix API:

// Real-time calculation
const response = await distanceMatrixAPI.getDistance(
  fromAddress,
  toAddress,
  'driving'
);

durationMin = Math.ceil(response.durationSeconds / 60);
distanceMeters = response.distanceMeters;

Walking Legs

Estimated at 5 km/h (83 meters/minute):

durationMin = Math.ceil(distanceMeters / 83);

// Example:
// 500 meters ÷ 83 = 6 minutes

Cost Structure

Bus Rides

All bus rides are free (university service):

{
  "mode": "bus",
  "cost": 0
}

Local Transport

Costs vary by distance (pre-configured in graph):

Distance	Cost (BDT)
< 1 km	15-20
1-2 km	20-25
2-4 km	25-35
> 4 km	35-50

{
  "mode": "local",
  "distanceMeters": 1200,
  "cost": 25
}

Walking

Always free:

{
  "mode": "walk",
  "cost": 0
}

Validation Rules

Required Field Validation

function validateLeg(leg: RouteLeg): boolean {
  // All legs must have these
  if (!leg.mode || !leg.from || !leg.to) {
    return false;
  }
  
  // Bus legs must have route info and timing
  if (leg.mode === 'bus') {
    if (!leg.route_id || !leg.trip_id || 
        !leg.departure || !leg.arrival || 
        leg.cost !== 0) {
      return false;
    }
  }
  
  // Cost must be non-negative
  if (leg.cost && leg.cost < 0) {
    return false;
  }
  
  return true;
}

Logical Consistency

// Duration should match departure/arrival for buses
if (leg.mode === 'bus') {
  const expectedDuration = 
    timeToMinutes(leg.arrival) - timeToMinutes(leg.departure);
  assert(leg.durationMin === expectedDuration);
}

// Walking and buses should be free
if (leg.mode === 'walk' || leg.mode === 'bus') {
  assert(leg.cost === 0);
}

// Local transport should have positive cost
if (leg.mode === 'local') {
  assert(leg.cost > 0);
}

Integration with RouteOption

Legs are always returned within a RouteOption:

{
  "label": "Fastest Route",
  "totalTimeMin": 56,
  "totalCost": 25,
  "legs": [
    { /* Bus leg */ },
    { /* Local leg */ }
  ]
}

The totals should match sum of legs:

const totalTime = legs.reduce((sum, leg) => sum + leg.durationMin, 0);
const totalCost = legs.reduce((sum, leg) => sum + leg.cost, 0);

RouteOption

Complete route containing multiple legs

Node

From/to location information

Bus Schedule

Trip timing for bus legs

Route Planning

API endpoint that returns legs

​Overview

​Type Definition

​Fields

​Leg Types

​Bus Leg

​Local Transport Leg

​Walking Leg

​Field Relationships

​Mode-Specific Fields

​Source Field

​Examples

​Single Bus Leg

​Bus + Local Transport

​Local + Walking

​Bus Transfer

​Calculating Leg Duration

​Bus Legs

​Local Transport Legs

​Walking Legs

​Cost Structure

​Bus Rides

​Local Transport

​Walking

​Validation Rules

​Required Field Validation

​Logical Consistency

​Integration with RouteOption

​Related Models

RouteOption

Node

Bus Schedule

Route Planning

Overview

Type Definition

Fields

Leg Types

Bus Leg

Local Transport Leg

Walking Leg

Field Relationships

Mode-Specific Fields

Source Field

Examples

Single Bus Leg

Bus + Local Transport

Local + Walking

Bus Transfer

Calculating Leg Duration

Bus Legs

Local Transport Legs

Walking Legs

Cost Structure

Bus Rides

Local Transport

Walking

Validation Rules

Required Field Validation

Logical Consistency

Integration with RouteOption

Related Models