9.3.3 Data and Input Parameters

9.3.3.1 HCM Method

The data and input requirements for the HCM Method are similar across software. This section focuses on the inputs necessary to conduct a segment analysis using HCS. For a detailed list of HCS input by segment type, see
Appendix J, Section 2 – HCS Data Inputs and Outputs by Segment Type
. Table 9-4 has a simplified list of the necessary data for each segment type.

9.3.3.2 Synchro

Synchro is typically used to analyze segments whose LOS is governed by intersection delay. Data inputs to Synchro include geometric data, lane settings, volume settings, timing settings, and phasing settings. For detailed inputs to a Synchro model, refer to the Synchro user guide.

9.3.3.3 TTI Frontage Road Analysis Procedures

Data requirements for a frontage road analysis are broken into two categories: one-way analysis inputs and two-way analysis inputs. A summary table of data inputs for each type of frontage road is shown in .
TTI Frontage Road Analysis Methodology Flowchart
Figure 9-2: TTI Frontage Road Analysis Methodology Flowchart
Table 9-4: Basic HCS Data Inputs by Segment Type
Segment Type
Corresponding HCS7 Analysis Type
Necessary Data
Freeways (Basic)
FREEWAYS →Freeways →Basic
  • Project Properties
  • Freeway Geometric Data
  • Demand Data
  • Adjustment Factors
Multi-lane Highways (Basic)
HIGHWAYS →Multilane
  • Project Properties
  • Highway Geometric Data
  • Demand Data
  • Adjustment Factors
Weaving
FREEWAYS →Freeways →Weaving
  • Project Properties
  • Freeway Geometric Data
  • Ramp Geometric Data
  • Demand Data
  • Freeway Adjustment Factors
Merge and Diverge
FREEWAYS →Freeways →Merge or Diverge
  • Project Properties
  • Freeway Geometric Data
  • Demand Data
  • Adjustment Factors
  • Adjacent Ramps
Two-lane Highways
HIGHWAYS →Two-lane
  • Project Properties
  • Highway Geometric Data
  • Demand Data
  • Subsegments
Arterial Facilities
STREETS →Streets
  • Traffic
  • Phasing
  • Timing
  • Detailed Input
Table 9-5: Data Inputs for Frontage Road Analysis
Type of Data
Data Necessary
Frontage Road
One-Way
Two-Way
Roadway Characteristics
Segment length (km)
Necessary
Necessary
Type of traffic control at intersections (e.g., no-control, stop-controlled, or traffic signal)
Necessary
Necessary
Number of all exit and entrance ramps
N/A
Necessary
Number of exit ramps without auxiliary lanes
Necessary
N/A
Segment access density, access/km (number of driveways and unsignalized intersections per kilometer)
Necessary
Necessary
Traffic Data
Frontage road approach volume at stop-controlled and signalized intersections, vehicles per hour (vph)
Necessary
Necessary
Ramp and frontage road volumes at all exit and entrance ramps, vph
N/A
Necessary
Exit ramp and frontage road volumes at exit ramps without auxiliary lanes, vph
Necessary
N/A
Signal Data
Signal progression data
Necessary
Necessary
Intersection capacity (c), vph
Necessary
Necessary
Cycle length (C), sec
Necessary
Necessary
Green/cycle time ratio (g/C)
Necessary
Necessary
Volume/capacity ratio (v/c)
Necessary
Necessary