HCM Chapter 16

Urban Street Facilities

Aggregate urban street segments into facility travel speed, spatial stop rate, and level of service for one direction of travel.

Open in Builder Takes this form to the facility builder as a Chapter 16 fixture. The builder recovers a boundary signal at each segment end, so the facility arrives editable as placed features.
Scope. The compute engine is boundary-validated against HCM Chapter 30, Example Problem 1 aggregated to facility level and against Chapter 29, Example Problem 1 in both directions, which the two modes' defaults reproduce. The page itself is in beta pending final inspection. Verify results independently before relying on them in engineering work, and please report discrepancies on GitHub.

Facility

How the segments are described, and the facility-wide inputs for the subject direction of travel.

Segment 1 · 1,800 ft11,800 ftSegment 2 · 1,800 ft21,800 ftSegment 3 · 1,800 ft31,800 ft

Segment chain, upstream to downstream, separated by its boundary intersections. Widths follow segment length, depth the through-lane count, and the ticks below each link are its subject-side access points. Click a segment to highlight its card.

Each segment is described by its Chapter 18 inputs and evaluated before the facility aggregation runs.

%

Used by the facility traveler perception score.

Segment 1

Chapter 18 inputs, ordered upstream to downstream.

ft

Stop line to stop line.

ln
mph
veh/h
veh/h
ft
ft
%
%
pts
pts
%

Use 0 for a full restrictive median with no openings.

ft
mph
s/veh

The Σ d_ap,i term of Equation 18-7, one measured or published value per active access point, comma separated. The defaults are the Exhibit 30-35 values for Example Problem 1. Blank falls back to the Exhibit 18-13 planning estimate. The third source, the Chapter 30 Section 4 computed procedure, takes per-approach geometry and turn volumes that this table has no room for; the Chapter 18 page offers it for a single segment.

The intersection at the downstream end of this segment.

s/veh

From the Chapter 19, 20, 21, or 22 analysis of the intersection.

veh/h

Needed for the critical v/c ratio and the Exhibit 16-3 LOS F check.

s
s

Blank gives uniform arrivals, P = g/C.

veh/h/ln
stops/veh

Needed for the facility stop rate and perception score at signalized boundaries.

Segment 2

Chapter 18 inputs, ordered upstream to downstream.

ft

Stop line to stop line.

ln
mph
veh/h
veh/h
ft
ft
%
%
pts
pts
%

Use 0 for a full restrictive median with no openings.

ft
mph
s/veh

The Σ d_ap,i term of Equation 18-7, one measured or published value per active access point, comma separated. The defaults are the Exhibit 30-35 values for Example Problem 1. Blank falls back to the Exhibit 18-13 planning estimate. The third source, the Chapter 30 Section 4 computed procedure, takes per-approach geometry and turn volumes that this table has no room for; the Chapter 18 page offers it for a single segment.

The intersection at the downstream end of this segment.

s/veh

From the Chapter 19, 20, 21, or 22 analysis of the intersection.

veh/h

Needed for the critical v/c ratio and the Exhibit 16-3 LOS F check.

s
s

Blank gives uniform arrivals, P = g/C.

veh/h/ln
stops/veh

Needed for the facility stop rate and perception score at signalized boundaries.

Segment 3

Chapter 18 inputs, ordered upstream to downstream.

ft

Stop line to stop line.

ln
mph
veh/h
veh/h
ft
ft
%
%
pts
pts
%

Use 0 for a full restrictive median with no openings.

ft
mph
s/veh

The Σ d_ap,i term of Equation 18-7, one measured or published value per active access point, comma separated. The defaults are the Exhibit 30-35 values for Example Problem 1. Blank falls back to the Exhibit 18-13 planning estimate. The third source, the Chapter 30 Section 4 computed procedure, takes per-approach geometry and turn volumes that this table has no room for; the Chapter 18 page offers it for a single segment.

The intersection at the downstream end of this segment.

s/veh

From the Chapter 19, 20, 21, or 22 analysis of the intersection.

veh/h

Needed for the critical v/c ratio and the Exhibit 16-3 LOS F check.

s
s

Blank gives uniform arrivals, P = g/C.

veh/h/ln
stops/veh

Needed for the facility stop rate and perception score at signalized boundaries.

Outputs

Results populate after pressing Calculate.

Facility Length (ft):
Facility Base Free-Flow Speed (mi/hr):
Facility Travel Speed (mi/hr):
Facility Travel Time (s):
Facility Spatial Stop Rate (stops/mi):
Critical Volume-to-Capacity Ratio:
Traveler Perception Score:
Poorest Segment LOS:

Facility LOS: