Analytical Procedures for Determining the Impacts of Reliability Mitigation Strategies (2012)

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172 A p p e n d i x A Data Elements and Structure for the Statistical Analysis Data Set Table A.1. Area Operations Category Variable Definition or Question Location URBAN_AREA Name of urban area where site is located TIME_SPAN Dates the data cover (typically 1 year) Service patrol (SP) AREA_SP_TRUCKS Number of SP trucks in active duty AREA_SP_TRUCKS_ACTIVE Percentage of total hours in a week when SP trucks are active AREA_SP_TRUCKS_MILE Trucks per route mile Incident management TIM_SA_OVERALL Traffic Incident Management Self-Assessment Score, Overall policies TIM_SA_PROGRAM_INSTITUTIONAL Traffic Incident Management Self-Assessment Score, Section 1 TIM_SA_OPERATIONAL_ISSUES Traffic Incident Management Self-Assessment Score, Section 2 TIM_SA_COMM_TECHNOLOGY Traffic Incident Management Self-Assessment Score, Section 3 QUICK_CLEARANCE_LAW Is a quick-clearance law in effect? PDO_MOVE_TO_SHOULDER_LAW Can property damage only (PDO) crashes be moved to shoulder by motorists? FATALITY_REMOVAL Can fatalities be moved without medical examiner death certification? Operations TMC_STAFF_MILE Number of traffic management center (TMC) staff divided by miles covered Table A.2. Service Patrols Category Variable Definition Location SHRP_SECTION Unique ID for this SHRP 2 study section TIME_SPAN Dates the data cover (typically 1 year) PERIOD Time slice (1 = peak hour; 2 = peak period; 3 = midday; 4 = weekday; 5 = weekend/ holiday; 6 = counterpeak; 7 = peak shoulder; 8 = all days) Service patrol SERVICE_PATROL_TRUCKS Number of SP trucks covering the section during the time period SERVICE_PATROL_SCHEDULE_PCT Percentage of time period when SP trucks are active SERVICE_PATROL_HOURS_MILE Truck hours per mile during time period

173 Table A.3. Bottleneck Off-Section Category Variable Definition Location SHRP_SECTION Unique ID for this SHRP 2 study section BOTTLENECK_NAME Unique name for this bottleneck ROUTE_NORTH_APPROACH Intersecting Route 1 ROUTE_SOUTH_APPROACH Intersecting Route 2 ROUTE_EAST_APPROACH Intersecting Route 3 ROUTE_WEST_APPROACH Intersecting Route 4 NB_EXIT_AADT_C Annual average daily traffic–to–capacity (AADT/C) ratio on the northbound exit to the bottleneck NB_EXIT_PEAK_PERIOD_D_C Peak period demand-to-capacity (d/c) ratio on the northbound exit to the bottleneck NB_EXIT_PEAK_HOUR_D_C Peak hour d/c ratio on the northbound exit to the bottleneck SB_EXIT_AADT_C AADT/C ratio on the southbound exit to the bottleneck SB_EXIT_PEAK_PERIOD_D_C Peak period d/c ratio on the southbound exit to the bottleneck SB_EXIT_PEAK_HOUR_D_C Peak hour d/c ratio on the southbound exit to the bottleneck EB_EXIT_AADT_C AADT/C ratio on the eastbound exit to the bottleneck EB_EXIT_PEAK_PERIOD_D_C Peak period d/c ratio on the eastbound exit to the bottleneck EB_EXIT_PEAK_HOUR_D_C Peak hour d/c ratio on the eastbound exit to the bottleneck WB_EXIT_AADT_C AADT/C ratio on the westbound exit to the bottleneck WB_EXIT_PEAK_PERIOD_D_C Peak period d/c ratio on the westbound exit to the bottleneck WB_EXIT_PEAK_HOUR_D_C Peak hour d/c ratio on the westbound exit to the bottleneck Table A.4. Section Characteristics Category Variable Definition Location URBAN_AREA Name of urban area where the site is located SHRP_SECTION Unique ID for this SHRP 2 study section TIME_SPAN Dates the data cover (typically 1 year) ROUTE From TMC configuration file DIR_TXT From TMC configuration file BEG_MILE_POINT Beginning log mile END_MILE_POINT Ending log mile Geometrics LNTH_QTY Length (mi) LANE_WIDTH Lane width (ft) AVG_NO_LANES Number of lanes (weighted average if number changes on section) TOTAL_ON_RAMPS Total number of on-ramps TOTAL_OFF_RAMPS Total number of off-ramps NO_LINKS Number of links comprising this section Traffic flow AADT_C_AVERAGE Vehicle miles traveled (VMT)–weighted average of link AADT/C ratios AADT_C_CRITICAL Maximum of link AADT/C ratios VMT_24_HOUR_TOTAL 24-hour VMT for entire time span Intelligent transportation system equipment NO_RAMP_METERS Number of ramp meters NO_CCTV Number of CCTV cameras NO_DMS Number of dynamic message signs

174 Table A.5. Section Events Category Variable Definition Location SHRP_SECTION Unique ID for this SHRP 2 study section TIME_SPAN Dates the data cover (typically 1 year) PERIOD Time slice (1 = peak hour; 2 = peak period; 3 = midday; 4 = weekday; 5 = weekend/ holiday; 6 = counterpeak; 7 = peak shoulder; 8 = all days) Weather PCT_HRS_RAIN_01 Percentage of hours when there was rain ≥0.01 inch PCT_HRS_RAIN_05 Percentage of hours when there was rain ≥0.05 inch PCT_HRS_RAIN_10 Percentage of hours when there was rain ≥0.1 inch PCT_HRS_RAIN_25 Percentage of hours when there was rain ≥0.25 inch PCT_HRS_RAIN_50 Percentage of hours when there was rain ≥0.50 inch PCT_HRS_RAIN_DRY_SPELL Percentage of hours when there was rain ≥0.01 inch after +30 days of no rain PCT_HRS_SNOW Percentage of hours when measurable snow fell PCT_HRS_UNFROZEN_PRECIP Percentage of hours when some form of precipitation was present PCT_HOURS_FROZEN_PRECIP Percentage of hours when snow, sleet, or freezing rain fell PCT_HOURS_FOG Percentage of hours when fog was reported Incidents INCIDENT_SOURCE Data source for incidents INCIDENT_LANE_HOURS_LOST Lane hours lost due to incidents INCIDENT_SHOULDER_HOURS_LOST Shoulder hours lost due to incidents INCIDENT_DURATION_AVERAGE Average incident duration INCIDENT_DURATION P95 95th percentile of incident duration NO_INCIDENTS Total number of incidents (all types) NO_CRASHES Total number of crashes NO_FATAL_CRASHES Number of fatal crashes NO_INJURY_CRASHES Number of injury crashes NO_PDO_CRASHES Number of PDO crashes NO_COMB_TRUCK_CRASHES Number of combination truck crashes Work zones WZ_SOURCE Data source for work zones WZ_LANE_HOURS_LOST Lane hours lost due to work zones WZ_SHOULDER_HOURS_LOST Shoulder hours lost due to work zones NO_WORK_ZONES Number of newly initiated work zones WZ_DURATION_AVERAGE Average work zone duration WZ_DURATION P95 95th percentile of work zone duration

175 Table A.6. Section Traffic Flow Category Variable Definition Location SHRP_SECTION Unique ID for this SHRP 2 study section TIME_SPAN Dates the data cover (typically 1 year) PERIOD Time slice (1 = peak hour; 2 = peak period; 3 = midday; 4 = weekday; 5 = weekend/holiday; 6 = counter peak; 7 = peak shoulder; 8 = all days) Traffic flow D_C_AVERAGE VMT-weighted average of link d/c ratios D_C_CRITICAL MAX (link d/c ratios) D_C_CRITICAL_DISTANCE (Distance of critical d/c link from downstream end) divided by section length VMT_TOTAL Sum of link VMT for this time span DVMT_AVERAGE Average daily VMT DVMT_STD_DEV Standard deviation of daily VMTs DVMT_HIGH_VARIABILITY_DAYS Number of days when VMT > (1.1 ∗ average daily VMT) Table A.7. Link Characteristicsa Category Variable Definition Location SHRP_SECTION Unique ID for this SHRP 2 study section TIME_SPAN Dates the data cover (typically 1 year) LINK_ID Link to which the station belongs ROUTE From TMC configuration file DIR_TXT From TMC configuration file BEG_MILE_POINT Beginning log mile END_MILE_POINT Ending log mile Geometrics LNTH_QTY Length of detector zone (zone of influence) for computing travel times NO_LANES Number of lanes LANE_WIDTH Lane width (ft) RIGHT_SHOULDER_WIDTH Right-shoulder width (ft) LEFT_SHOULDER_WIDTH Left-shoulder width (ft) NO_ON_RAMPS Number of on-ramps NO_OFF_RAMPS Number of off-ramps WEAVING_TYPE Type of weaving section SPEED_LIMIT Speed limit (mph) HCM_CAPACITY HCM capacity (continued on next page)

176 Table A.8. Link Traffic Flowa Category Variable Definition Location SHRP_SECTION Unique ID for this SHRP 2 study section TIME_SPAN Dates the data cover (typically 1 year) LINK_ID Link to which the station belongs PERIOD Time slice (1 = peak hour; 2 = peak period; 3 = midday; 4 = weekday; 5 = weekend/ holiday; 6 = counter peak; 7 = peak shoulder; 8 = all days) Traffic Statistics VOLUME_MEASURED_AVERAGE Straight average of measured volumes for this period VOLUME_DEMAND_AVERAGE Average of demand volumes (calculated) VOLUME_MEASURED_STD_DEV Standard deviation of measured volumes VOLUME_DEMAND_STD_DEV Standard deviation of demand volumes VOLUME_HIGH_VARIABILITY_DAYS Number of days when volume > (1.1 ∗ average demand volume) PCT_AADT Average demand volume divided by AADT D_C Demand-to-capacity ratio a Data on basic traffic flow by time period for each link. Traffic summaryb AADT AADT, computed from the data AADT_OTHER AADT (secondary value) AADT_OTHER_SOURCE Other sources of AADT (e.g., Highway Performance Monitoring System) AADT_STD_DEV Standard deviation of directional average daily traffic (DADT) that goes into AADT calculation AWDT Average weekday daily traffic (AWDT) AWDT_STD_DEV Standard deviation of DADTs that go into AWDT calculation AWEHDT Average weekend/holiday daily traffic AWEHDT_STD_DEV Standard deviation of DADTs that go into average weekend/holiday daily traffic calculation K_FACTOR Peak hour K-factor, computed from the data PCT_TRUCKS Percentage trucks AADT_C AADT/C ratio PHV_PPV Peak hour demand volume divided by peak period demand volume PCT_IMPUTED Percentage of original records for which volume has been imputed a Data about the links (segments) and traffic summaries. b If two detectors exist on a link, then one must be selected as the representative detector. Table A.7. Link Characteristicsa (continued) Category Variable Definition