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