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 .

Figure 9-2: TTI Frontage Road Analysis Methodology Flowchart
Segment Type | Corresponding HCS7 Analysis Type | Necessary Data |
---|---|---|
Freeways (Basic) | FREEWAYS →Freeways →Basic |
|
Multi-lane Highways (Basic) | HIGHWAYS →Multilane |
|
Weaving | FREEWAYS →Freeways →Weaving |
|
Merge and Diverge | FREEWAYS →Freeways →Merge or Diverge |
|
Two-lane Highways | HIGHWAYS →Two-lane |
|
Arterial Facilities | STREETS →Streets |
|
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 |