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 |