WF-TDM Non-Motorized Enhancement
2026-07-02
Test geography: 5 small districts (278 TAZs) across the region
What we changed:
| Group | Scenarios |
|---|---|
| Households only | 2×, 4×, 12× |
| Employment only | 2×, 4×, 12× |
| Both HH + EMP | 2×, 4×, 12× |
| 2050 land use (local) | Base & Centerized |
| 2050 land use (region) | Base & Centerized |
What we measured: Non-motorized mode share — the share of daily productions walked or biked
Why such extreme multipliers?
The 2×, 4×, and 12× values are intentionally unrealistic. They stress-test the model across a wide range of densities so we can understand its behavior — not to represent actual planning scenarios.
All trip purposes combined | Modified small districts | Daily productions
| Scenario | NM Share | vs. Base |
|---|---|---|
| Base 2019 | 16.1% | — |
| HH only ×4 | 18.7% | +2.6 pct pts |
| EMP only ×4 | 31.1% | +15.0 pct pts |
| HH + EMP ×4 | 29.5% | +13.5 pct pts |
| Scenario | NM Share | vs. Base |
|---|---|---|
| Base 2019 | 16.1% | — |
| HH only ×12 | 28.5% | +12.4 pct pts |
| EMP only ×12 | 51.3% | +35.2 pct pts |
| HH + EMP ×12 | 49.5% | +33.4 pct pts |
Important
At equal multipliers, employment density produces a bigger non-motorized mode share gain than household density alone — roughly 5–6× bigger at ×4, narrowing to roughly 2.5–3× at ×12 as the response saturates.
Why is HH + EMP lower than EMP alone?
Mode share is a percentage, and household growth adds trips of every kind — including car trips leaving the area — which grows total trip volume faster than it grows walking/biking trips. At ×12, HH + EMP actually has ~4× more non-motorized trips than EMP alone (3.2M vs. 824K), just spread across a much bigger pool of total trips (6.5M vs. 1.6M) — so the percentage comes out slightly lower even though non-motorized activity is far higher.
Home-Based-Other and Non-Home–Based trips are the most sensitive to employment density — these include lunch, errands, and midday travel that become walkable in dense employment environments.
EMP scenarios: walk gains are 10–100× larger than bike gains. HH scenarios: both modes increase, but walk still dominates.
| Scenario | Local HH | Local EMP | Region HH | Region EMP |
|---|---|---|---|---|
| Base 2019 | +0% | +0% | +0% | +0% |
| Future Today | +108% | +61% | +76% | +46% |
| Future Today - Centerized | +118% | +61% | +76% | +46% |
Locally, households roughly double (+108%) and employment grows +61% — much more concentrated than the region-wide totals (+76% HH, +46% EMP), since these test districts were picked for their concentrated growth. Centerization redistributes some additional household growth into the districts (+118%) without changing region-wide totals at all.
2050 local forecasts land at ~19.4% — comparable to a 2× multiplier — a moderate, credible response. Region-wide, the gain is smaller: from 11.0% to 11.8% (+0.8 percentage points).
Districts gaining households (blue) → Non-Motorized share rises. Districts losing households (orange) → Non-Motorized share falls.
The model passes the test — NM mode share increases consistently and proportionally with density increases in the expected direction.
Employment density is the primary lever — at equal multipliers, EMP produces 2–2.5× more NM mode share gain than households.
Walk trips, not bike, drive the gains — especially in high-employment scenarios.
Home-Based-Other and Non-Home–Based trips are most sensitive — short-trip purposes respond most to walkable environments.
2050 forecasts are in a reasonable range — comparable to roughly 2× current density, not extreme.
Wasatch Front Regional Council | Non-Motorized Sensitivity Analysis