Travel Demand Forecasting (4-Step Model) — Ebora Transportation Engineering

🗺️ Travel-Demand Forecasting · 4-Step Model

Travel Demand Forecasting (4-Step Model)

Run the classic urban-transportation-planning sequence over a small study area in one tap: ① trip generation (balance attractions), ② trip distribution (gravity model → the OD trip matrix), ③ modal split (multinomial logit), and ④ trip assignment (all-or-nothing + BPR). Fill the four steps below, then run the full forecast.

⭐ Free to run · Balance … EP

① Trip generation — productions & attractions (3 zones)

Enter each zone's trip productions Pᵢ (origins) and attractions Aⱼ (destinations). Attractions are scaled so ΣA = ΣP (production-constrained balancing).

Zone	Productions P (trips)	Attractions A (trips)
1
2
3

② Trip distribution — gravity model

Travel-time (impedance) matrix tᵢⱼ in minutes between zones — diagonal tᵢᵢ are small intrazonal times. Tᵢⱼ = Pᵢ · (Aⱼ Fᵢⱼ) / Σₖ(Aₖ Fᵢₖ), so each row sums to Pᵢ exactly.

Impedance matrix t (min) — rows = origin, cols = destination

from \ to	Zone 1	Zone 2	Zone 3
Zone 1
Zone 2
Zone 3

Friction factor F(t)

Parameter (b)

③ Modal split — multinomial logit

Enter each mode's utility Uₘ directly (build it however you like, e.g. U = −0.02·cost − 0.03·time + ASC). Shareₘ = e^{Uₘ} / Σ e^{Uₙ}; applied to the total trips Σᵢⱼ Tᵢⱼ.

Number of modes

Mode name

Utility U

Mode name

Utility U

④ Trip assignment — all-or-nothing (one OD pair)

All demand V loads onto the route with the smallest free-flow time t₀, then BPR gives its congested time t = t₀(1 + α(V/cap)^β). Leave a route's t₀ blank to skip it.

Auto volume to assign V (veh) — optional override; default = top mode's trips Candidate routes (one OD pair)

Route	Free-flow t₀ (min)	Capacity (veh/h)
1
2
3

BPR α

BPR β

🗺️ 4-step forecast

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Sequential travel-demand model

Total productions ΣP

—

Total trips ΣΣTᵢⱼ

—

Modes

—

Assigned volume V

—

Chosen route

—

Congested time

—

① Balanced attractions

Zone	Productions P	Attractions A (raw)	Attractions A (balanced)

② OD trip matrix Tᵢⱼ

from \ to	Zone 1	Zone 2	Zone 3	Row total = Pᵢ

③ Modal split

Mode	Utility U	Share %	Trips

④ Trip assignment (all-or-nothing + BPR)

Route	Free-flow t₀ (min)	Capacity (veh/h)	Volume (veh)	Congested t (min)