Residents’ traffic study

Traffic on Route 9 and Route 9D

How long it takes to drive the two roads through Wappingers Falls, and how fast traffic moves, at every half hour of the week. These are the roads the 198 homes proposed at “The Ridge” would feed into.

Offline scenario model

Simulate 198 apartments at The Ridge

Change any assumption and the browser reruns the same deterministic corridor calculation used by the offline task. No AI service, map API or database call is used.

1,030

weekday vehicle trip ends

75.2

AM peak-hour trip ends

PM peak-hour trip ends

+7.4 sec

largest modeled corridor increase

Worst-case stress test

With 115% development demand applied to the slowest measured speed in every direction, the lowest result is US Route 9 southbound: 15.2 → 15.2 mph. The largest change is NY Route 9D northbound PM: 17.2 → 16.9 mph (+10.8 seconds).

This deliberately conservative stress test combines directional minima that may have occurred at different times.

Scenario range

Scenario	Demand	Daily trips	AM peak	PM peak	Largest added time
Low demand	85%	875	64	80.8	+6.2 sec
Central	100%	1,030	75.2	95	+7.4 sec
High demand	115%	1,184	86.5	109.3	+8.6 sec
Worst traffic + high demandslowest measured baseline	115%	1,184	86.5	109.3	+10.8 sec

Central scenario by corridor

Peak	Road and direction	Existing vph	Added vph	Volume/capacity	Travel time	Average speed	Change
AM	NY Route 9D southbound	651	+43.5	0.72 → 0.77	8.8 → 8.9 min	21.6 → 21.4 mph	+6.2 sec
AM	NY Route 9D northbound	533	+31.8	0.59 → 0.63	8.1 → 8.1 min	23.5 → 23.4 mph	+2.3 sec
AM	US Route 9 northbound	2,243	+20.6	0.62 → 0.63	4.8 → 4.8 min	28.4 → 28.4 mph	+0.2 sec
AM	US Route 9 southbound	1,835	+18.5	0.51 → 0.52	5.2 → 5.2 min	26.2 → 26.2 mph	+0.1 sec
PM	NY Route 9D southbound	533	+43.8	0.59 → 0.64	8.9 → 9.0 min	21.4 → 21.2 mph	+3.6 sec
PM	NY Route 9D northbound	651	+51.2	0.72 → 0.78	8.8 → 8.9 min	21.6 → 21.3 mph	+7.4 sec
PM	US Route 9 northbound	1,835	+24.1	0.51 → 0.52	5.3 → 5.3 min	25.7 → 25.7 mph	+0.2 sec
PM	US Route 9 southbound	2,243	+25.4	0.62 → 0.63	6.5 → 6.5 min	21.0 → 20.9 mph	+0.4 sec

Parameters and definitions

Every value used by the calculation is listed here. Open a group to inspect or change it.

ApartmentsunitsNumber of proposed dwelling units. The current Ridge concept contains 198 apartments.Starting source: Ridge concept planOccupied units%Share of apartments assumed occupied when the development is fully built.Weekday vehicle trip ends per occupied unittrips/unit/dayOne vehicle entering or leaving is one trip end. This planning assumption must be replaced with the applicable licensed ITE rate or an accepted local study before formal use.AM peak-hour trip ends per occupied unittrips/unit/hourVehicle trip ends generated during the analyzed morning peak hour.PM peak-hour trip ends per occupied unittrips/unit/hourVehicle trip ends generated during the analyzed evening peak hour.AM trips entering%Share of AM development trips arriving at the apartments. The remainder exits.PM trips entering%Share of PM development trips arriving at the apartments. The remainder exits.Trips reaching public roads%Share of generated trips that reaches the modeled public-road network after any justified internal-capture or other reductions.

Trips using Route 9D toward US 9%Share of Ridge traffic assigned south on Route 9D toward its US 9 junction. The remainder uses Route 9D north.South-assigned trips continuing onto US 9%Share of traffic reaching the Route 9D/US 9 area that continues on US 9 instead of ending on local streets or at nearby destinations.US 9 trips oriented north%Share of US 9 traffic whose external origin or destination is north of the Route 9D junction. The remainder is oriented south.

Repeat it offline

npm run dv:simulate-ridge

The task reads src/data/dv-ridge-simulation-defaults.json and writes the complete, deterministic result to public/studies/traffic/ridge-simulation.json. Pass --input and --output after -- to run a saved alternative scenario.

What this model can and cannot say

This is a corridor screening model. It uses directional assignment and the Bureau of Public Roads volume-delay curve to estimate how added hourly traffic changes average corridor time. It does not simulate individual signals, turn lanes, driveway queues, crashes or spillback. The worst-case stress test combines each direction’s slowest measured speed even though those minima may not have occurred together. The trip rates, direction splits, capacities and baseline times remain visible because measured turning counts and an engineer-reviewed intersection model are required before treating the results as a formal traffic-impact study.

Population density

Show

US Route 9: Vassar Rd junction to south of Myers Corners Rd

2.27 miles each way

17.6 mph

Slowest typical time

southbound, Tue 5:30 pm: 7.8 min

10.5 mph

Google’s worst-case estimate

southbound, Tue 5:30 pm: 13 min

39.8 mph

Quietest time of the week

northbound, Thu 3 am: 3.4 min

15.2 mph

Slowest measured so far

southbound, Thu 2:30 pm (336 samples each way)

Average speed by time of day

Slowest half-hours of the week

When	Direction	Typical	Worst-case estimate
Tue 5:30 pm	southbound	7.8 min · 17.6 mph	13 min · 10.5 mph
Thu 5:30 pm	southbound	7.5 min · 18.2 mph	13 min · 10.5 mph
Tue 5 pm	southbound	7.3 min · 18.7 mph	12 min · 11.4 mph
Fri 3 pm	southbound	7.1 min · 19.2 mph	12.2 min · 11.2 mph
Wed 5:30 pm	southbound	7.1 min · 19.3 mph	12.5 min · 11 mph
Wed 4:30 pm	southbound	7 min · 19.6 mph	12.1 min · 11.3 mph

Route 9D: Route 9 junction, through Wappingers Falls, to Hughsonville

3.17 miles each way

19.2 mph

Slowest typical time

southbound, Thu 5:30 pm: 9.9 min

13.1 mph

Google’s worst-case estimate

southbound, Tue 5:30 pm: 14.5 min

34.5 mph

Quietest time of the week

southbound, Sun 4:30 am: 5.5 min

16.2 mph

Slowest measured so far

southbound, Thu 5:30 pm (336 samples each way)

Average speed by time of day

Slowest half-hours of the week

When	Direction	Typical	Worst-case estimate
Thu 5:30 pm	southbound	9.9 min · 19.2 mph	14.2 min · 13.4 mph
Wed 5 pm	southbound	9.7 min · 19.7 mph	13.6 min · 14 mph
Tue 5:30 pm	southbound	9.6 min · 19.8 mph	14.5 min · 13.1 mph
Fri 5 pm	northbound	9.6 min · 19.9 mph	13.4 min · 14.2 mph
Wed 5:30 pm	southbound	9.5 min · 20 mph	13.5 min · 14.1 mph
Fri 5:30 pm	southbound	9.5 min · 20 mph	13.8 min · 13.8 mph

How these numbers were made

Typical and worst-case estimates are Google Maps’ own predictions for each half hour of the week of September 28, 2026, built from its record of past traffic on these roads. The worst-case estimate is Google’s pessimistic prediction, which Google intends to be longer than the actual trip on most days; only unusually bad traffic takes longer.
Measured points are Google’s live travel time, asked every 30 minutes (336 checks so far).
Speed is the route’s length divided by the travel time, so it includes time waiting at lights and turns, not just speed while moving.
Each road is timed over the same stretch in both directions. The map shows the stretches.