National Academies Press: OpenBook

Multimodal Level of Service Analysis for Urban Streets (2008)

Chapter: Chapter 2 - State of the Practice

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Suggested Citation:"Chapter 2 - State of the Practice." National Academies of Sciences, Engineering, and Medicine. 2008. Multimodal Level of Service Analysis for Urban Streets. Washington, DC: The National Academies Press. doi: 10.17226/14175.
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Suggested Citation:"Chapter 2 - State of the Practice." National Academies of Sciences, Engineering, and Medicine. 2008. Multimodal Level of Service Analysis for Urban Streets. Washington, DC: The National Academies Press. doi: 10.17226/14175.
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Suggested Citation:"Chapter 2 - State of the Practice." National Academies of Sciences, Engineering, and Medicine. 2008. Multimodal Level of Service Analysis for Urban Streets. Washington, DC: The National Academies Press. doi: 10.17226/14175.
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Suggested Citation:"Chapter 2 - State of the Practice." National Academies of Sciences, Engineering, and Medicine. 2008. Multimodal Level of Service Analysis for Urban Streets. Washington, DC: The National Academies Press. doi: 10.17226/14175.
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Suggested Citation:"Chapter 2 - State of the Practice." National Academies of Sciences, Engineering, and Medicine. 2008. Multimodal Level of Service Analysis for Urban Streets. Washington, DC: The National Academies Press. doi: 10.17226/14175.
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Suggested Citation:"Chapter 2 - State of the Practice." National Academies of Sciences, Engineering, and Medicine. 2008. Multimodal Level of Service Analysis for Urban Streets. Washington, DC: The National Academies Press. doi: 10.17226/14175.
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Suggested Citation:"Chapter 2 - State of the Practice." National Academies of Sciences, Engineering, and Medicine. 2008. Multimodal Level of Service Analysis for Urban Streets. Washington, DC: The National Academies Press. doi: 10.17226/14175.
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Suggested Citation:"Chapter 2 - State of the Practice." National Academies of Sciences, Engineering, and Medicine. 2008. Multimodal Level of Service Analysis for Urban Streets. Washington, DC: The National Academies Press. doi: 10.17226/14175.
×
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Suggested Citation:"Chapter 2 - State of the Practice." National Academies of Sciences, Engineering, and Medicine. 2008. Multimodal Level of Service Analysis for Urban Streets. Washington, DC: The National Academies Press. doi: 10.17226/14175.
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Suggested Citation:"Chapter 2 - State of the Practice." National Academies of Sciences, Engineering, and Medicine. 2008. Multimodal Level of Service Analysis for Urban Streets. Washington, DC: The National Academies Press. doi: 10.17226/14175.
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Suggested Citation:"Chapter 2 - State of the Practice." National Academies of Sciences, Engineering, and Medicine. 2008. Multimodal Level of Service Analysis for Urban Streets. Washington, DC: The National Academies Press. doi: 10.17226/14175.
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Suggested Citation:"Chapter 2 - State of the Practice." National Academies of Sciences, Engineering, and Medicine. 2008. Multimodal Level of Service Analysis for Urban Streets. Washington, DC: The National Academies Press. doi: 10.17226/14175.
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5This chapter summarizes the state of the practice in the United States with regard to multimodal LOS analysis and identifies needed improvements. The review includes national and state guides on LOS analysis and profiles of typical and state-of-the-art applications of modal and multimodal LOS by public agencies in the United States. 2.1 State-of–the-Practice Survey A brief state-of-the-practice survey was conducted of a few selected representative public agencies to determine how public agencies currently use level of service. Exhibit 1 lists the people and agencies contacted. The state-of-the-practice survey identified three major professional manuals typically referenced by public agencies when computing multimodal highway level of service. These manuals are the Highway Capacity Manual [1], the Transit Capacity and Quality of Service Manual [2], and Florida’s Quality/Level of Service Handbook [3]. The portions of these manuals relevant to the current research are summarized in the following subsections. Highway Capacity Manual The Highway Capacity Manual (HCM) provides LOS measures, thresholds, and estimation procedures for auto, transit, bicycle, and pedestrian modes. Urban Street LOS Chapter 15 of the HCM defines urban street LOS according to the mean speed of through traffic on an urban street. The pre- cise thresholds vary by urban street class (see Exhibit 2), which affects the presumed mid-block free-flow speed on each street. When one takes into account the differing typical free-flow speeds for the urban street classes, the speed breakpoint for LOS A averages about 85% of the typical mid-block free-flow speed, LOS B averages 67%, LOS C averages 51%, LOS D averages 39%, and LOS E averages 29%. The HCM provides a methodology for estimating the mean speed for through traffic on an urban street. The methodology reduces the mid-block free-flow speed accord- ing to the average delay to through traffic at each traffic signal. This speed is further reduced to account for delays between signals due to short signal spacing (called “segment running time” in the HCM). The effects of signal progression are taken into account in the computation of mean delay at each signal. For comparison with the other model forms discussed later, the HCM look-up table can be expressed (approxi- mately) in the form of a linear function of facility type and speed, as follows: LOS = Integer{0.151231 * Speed + 0.636927 * Class − 2.17765} (Eq. 1) Where LOS = HCM LOS Integer Scale (where A=5, F = 0) Integer = The integer function (rounds off the value to the nearest integer value). Speed = Mean speed of through traffic on arterial in mph. Class = Arterial Class as defined by HCM (Class 1, 2, 3, or 4) (R-Square = 0.97, all variables significant) Transit LOS Chapter 27 of the HCM provides four transit LOS measures, adapted from the six presented in the Transit Capacity and Quality of Service Manual, First Edition: Service Frequency, Hours of Service, Passenger Load, and Service Reliability. These measures are presented below under the Transit Capac- ity and Quality of Service Manual section. C H A P T E R 2 State of the Practice

6Contact Agency Location Geographic US Agency Type 1. Conan Cheung MTDB San Diego, CA West Transit Operator 2. Douglas Dalton Wisconsin DOT Milwaukee, WI Central DOT 3. Doug McLeod Florida DOT Tallahassee, FL East DOT 4. Juan Robles Colorado DOT Denver, CO Mountain DOT 5. James Okazaki Los Angeles DOT Los Angeles, CA West City 6. Carolyn Gonot Santa Clara VTA San Jose, CA West CMA/Transit 7. Jim Altenstadter PIMA AG Tucson, AZ Mountain MPO 8. John Halkias FHWA Washington, DC East Federal Exhibit 1. Contacts for State of Practice Survey. Bicycle LOS Chapter 19 of the HCM provides bicycle LOS criteria, thresholds, and estimation procedures for off-street paths and designated bicycle lanes on urban streets (summarized in Exhibit 3 and 4). It is based on research conducted for the FHWA [4]. The HCM provides procedures for estimating mean bicy- cle speed and mean control delay. The mean control delay is estimated based on the signal timing at each signal. The mean speed is estimated by reducing the presumed 15 mph bicycle free-flow speed by the delay at each signal. For off-street bicycle/pedestrian paths, the HCM-adopted bicycle LOS criterion is based on the frequency of encounters (i.e. passing and meeting events) between bicyclists and pedestrians on the path. For two-way, two-lane paths, less than 40 encounters per hour is LOS A. More than 195 encounters per hour is LOS F. A procedure is provided for estimating the number of encounters based on pedestrian and bicycle volumes. Pedestrian LOS Chapter 18 of the HCM provides pedestrian LOS criteria, thresholds, and estimation procedures for sidewalks, street corners, crosswalks, and off-street paths. It is based on research conducted for the FHWA [5]. For sidewalks, the key service criterion is space per pedes- trian (inverse of density) (see Exhibit 5). A procedure is pro- vided for estimating this based on facility width and pedestrian volumes. These are based on observations from Fruin [6]. For shared bicycle and pedestrian paths, the pedestrian LOS is computed according to the expected number of bicycle-pedestrian encounters per hour (see Exhibit 6). The criteria and thresholds are based on research by Botma [7]. A procedure is provided for estimating this based on pedes- trian and bicycle volumes. At signalized intersections, the pedestrian LOS is measured using average delay to the pedestrians waiting to cross the streets (see Exhibit 7). A procedure is provided for estimating delay based on the pedestrian or vehicle signal timing. Average crossing delay is also used to estimate pedestrian LOS for unsignalized intersections. The LOS thresholds are more conservative (less than 5 seconds of delay equals LOS A. More than 45 seconds of delay equals LOS F). For urban streets with sidewalks, the HCM bases the pedestrian level of service on mean speed over the length of the street (see Exhibit 8). The average walking speed between intersections is reduced according to the average wait time at each intersection to arrive at a mean walking speed for the length of the urban street. Transit Capacity and Quality of Service Manual TCRP Report 100: Transit Capacity and Quality of Service Manual, 2nd Edition (TCQSM) presents a two-dimensional LOS framework. It is a matrix covering two service quality dimensions (i.e., Availability and Comfort & Convenience) for three transit system elements (i.e., Stops, Route Segments, and Systems) (see Exhibit 9). Each of the six cells of the ma- trix provides a service measure for which levels of service are Urban Street Class I II III IV Range of FFS 45-55 mph 35-45 mph 30-35 mph 25-35 mph Typical FFS 50 mph 40 mph 35 mph 30 mph LOS A >42 mph > 35 mph >30 mph >25 mph B >34-42 >28-35 >24-30 >19-25 C >27-34 >22-28 >18-24 >13-19 D >21-27 >17-22 >14-18 >9-13 E >16-21 >13-17 >10-14 >7-9 F ≤16 ≤13 ≤10 ≤7 FFS = mid-block free-flow speed of street. Exhibit adapted from Exhibit 15-2, Highway Capacity Manual Exhibit 2. Urban Street Level of Service.

7LOS Average Bicycle Speed A > 14 mph B >9-14 C >7-9 D >5-7 E ≥4-5 F <4 Adapted from Exhibit 19-5 of the Highway Capacity Manual. Exhibit 3. HCM Bicycle LOS for Bicycle Lanes on Urban Streets. LOS Space/Pedestrian A >60 S.F. B >40-60 C >24-40 D >15-24 E >8-15 F ≤8 S.F. = square feet. Adapted from Exhibit 18-3 of the Highway Capacity Manual Exhibit 5. HCM Pedestrian LOS Criteria for Sidewalks. For transit route segments and corridors, the hours of ser- vice each day (i.e., the number of hours per day when service is available at least hourly) is the LOS criterion (see Exhibit 11). For route segments and corridors where stops are made, service frequency would also be evaluated at the individual stops (depending on routing and scheduling patterns, not all buses may stop at every stop). At the system level, the service coverage area as a per- centage of the transit supportive area is the LOS criterion. The transit supportive area is defined as the area with a minimum density of four jobs per gross acre or three dwellings per gross acre, based on work by Pushkarev and Zupan [8]. The transit service coverage area is that area developed; the TCQSM 1st Edition (TCRP Web-Only Docu- ment 6) also provided one or more other performance meas- ures also thought to be important to consider. Lower-level measures (e.g., stop level) are also applicable at higher levels (i.e., the route segment or system levels). The TCQSM distinguishes between demand-responsive transit and fixed-route transit service. The LOS criteria for fixed-route transit service are covered in this review. Availability Measures of Level of Service For transit stops the frequency of service is the LOS crite- rion (see Exhibit 10). LOS Average Control Delay A < 10 secs B ≥10-20 C >20-30 D >30-40 E >40-60 F >60 Adapted from Exhibit 19-4 of the Highway Capacity Manual. Exhibit 4. HCM Bicycle LOS at Signals. LOS Encounters/hour A ≤38 B >38-60 C >60-103 D >103-144 E >144-180 F >180 Adapted from Exhibit 18-8 of the Highway Capacity Manual Exhibit 6. HCM Pedestrian LOS Criteria for Paths. LOS Average Crossing Delay A < 10 secs B ≥10-20 C >20-30 D >30-40 E >40-60 F >60 Adapted from Exhibit 18-9 of the Highway Capacity Manual. Exhibit 7. HCM Pedestrian LOS at Signals. LOS Mean Walking Speed A > 4.36 fps B >3.84-4.36 C >3.28-3.84 D >2.72-3.28 E >1.90-2.72 F < 1.90 fps fps = feet per second. Adapted from Exhibit 18-14 of the Highway Capacity Manual. Exhibit 8. HCM Pedestrian LOS for Urban Streets. LOS Dimension Transit Stop Route Segment System Availability Frequency Hours of Service Coverage Comfort & Convenience Load Factor Reliability Time Differences Adapted from Exhibit 3-1, Transit Capacity and Quality of Service Manual Exhibit 9. TCQSM Two-Dimensional LOS Framework.

8LOS Vehicles Per Hour A > 6 B 5 to 6 C 3 to 4 D 2 E 1 F < 1 Adapted from Exhibit 27-1 of the Highway Capacity Manual. Exhibit 10. TCQSM Service Frequency LOS. within the transit supportive area that lies within one- quarter air mile of a stop. Greater than 90% is LOS A. Less than 50% is LOS F. Comfort & Convenience Measures of LOS For transit stops, the TCQSM “comfort and convenience” measure of level of service is based on passenger load (see Exhibit 12). For typical bus services operating on urban streets, where most passengers would be seated, LOS A-C is based on the load factor (i.e., total number of passengers divided by the number of seats), while LOS D-F is based on the average area per person available for standees. This meas- ure originated in the 1985 HCM. For route segments and corridors, the comfort and con- venience level of service measure is “on-time performance” and headway adherence. For scheduled service of fewer than six vehicles per hour, Exhibit 13 is used. For scheduled service of six vehicles per hour or greater the reliability LOS is according to Exhibit 14. The on-time performance measure applies to all services with a published timetable, and its LOS thresholds are all in 5% increments, with the LOS E/F threshold set at 75%. The headway adherence measure now applies to all services scheduled to a headway or operating at headways of 10 min- utes or less (thus, both measures could apply to some routes). The measure definition allows for variable headways during the peak hour, and the LOS thresholds correspond to the probability that no more than a certain percentage of transit vehicles would be more than one-half headway off schedule. For the system level, the LOS criterion is door-to-door “travel time difference” between driving a car and taking transit. If transit takes 60 minutes longer than driving, it is LOS F for transit. If they are equal, or transit is faster, it is LOS A for transit. In addition to the LOS measures presented in the Quality of Service section of the TCQSM, the Stop, Station, and Ter- minal Capacity section presents a series of pedestrian levels of service for elements of passenger facilities, such as walkways and stairways, based on work by Fruin (same reference as pre- vious). These levels of service are presented more for design purposes (e.g., sizing a station element to provide a certain level of service) than for evaluating existing facilities. These levels of service are similar to, but have different thresholds LOS Hours Per Day A 19-24 B 17-18 C 14-16 D 12-13 E 4-11 F 0-3 Adapted from Exhibit 27-4 of the Highway Capacity Manual. Exhibit 11. TCQSM Hours of Service LOS. LOS On-Time Percentage A 95.0-100.0% B 90.0-94.9% C 85.0-89.9% D 80.0-84.9% E 75.0-79.9% F <75% Applies to scheduled service of fewer than six vehicles per hour. Adapted from Exhibit 3-29 of the TCQSM. Exhibit 13. TCQSM Reliability LOS for Infrequent Urban Scheduled Transit Service. LOS Standing Passenger Area (ft 2 /p) Load Factor A >10.8 0.00-0.50 B 8.2-10.8 0.51-0.75 C 5.5-8.1 0.76-1.00 D 3.9-5.4 1.01-1.25 E 2.2-3.8 1.26-1.50 F <2.2 >1.50 Adapted from Exhibit 3-26 of the TCQSM. Exhibit 12. TCQSM Passenger Load LOS for Bus. LOS Coefficient of Variation A 0.00-0.21 B 0.22-0.30 C 0.31-0.39 D 0.40-0.52 E 0.53-0.74 F ≥0.75 Applies to scheduled service of six or more vehicles per hour. The coefficient of variation is the ratio of the standard deviation of headway deviations divided by the mean scheduled headway. Headway deviations are measured as the actual headway minus the scheduled headway. Adapted from Exhibit 3-30 of the TCQSM. Exhibit 14. TCQSM Reliability LOS for Frequent Urban Scheduled Transit Service.

9than, the HCM pedestrian measures, as the TCQSM meas- ures are intended for transit facilities, while the HCM meas- ures are intended for sidewalks. However, the TCQSM’s pedestrian waiting area measure would be applicable to bus stops along arterial streets. Florida Quality/Level of Service Handbook The Florida Q/LOS Handbook provides LOS measures, thresholds, and estimation methodologies for auto, transit, bicycle, and pedestrian modes. Auto LOS The FDOT handbook uses the urban street LOS criteria and thresholds contained in the Urban Streets chapter of the Highway Capacity Manual. Various default values are pro- vided for some of the more difficult to obtain input data. Transit LOS The transit level of service method and thresholds in the FDOT handbook are designed to be applied only to fixed- route, fixed-schedule bus service. The bus LOS thresholds are keyed to the adjusted service frequency (see Exhibit 15). The actual service frequency is reduced (or increased) depending on the hours of daily operation of the bus service (see Exhibit 16), the difficulty of crossing the street on foot (see Exhibit 17), and the difficulty of walking the length of the street segment (see Exhibit 18). ASF = SF * PLOSAdj * CrossAdj * SpanAdj (Eq. 2) Where ASF = Adjusted Service Frequency (vph) SF = Actual Service Frequency (vph) PLOSAdj = Adjustment factor for pedestrian LOS CrossAdj = Adjustment factor for street crossing difficulty for pedestrians SpanAdj = Adjustment factor for daily hours of bus service. The FDOT Q/LOS Handbook uses the HCM LOS criteria and thresholds for urban streets for the automobile level of service. The Handbook provides two LOS estimation procedures for planning level analyses: Generalized Planning Analysis, and Conceptual Planning Analysis. Generalized planning analysis is a “broad type of planning application such as statewide analyses, initial problem identification, and future year analyses.” Conceptual planning is a “preliminary engi- neering application detailed enough to reach a decision on design concept and scope.” Generalized planning analysis consists of look-up tables of maximum service volumes for auto LOS by facility type, area type, number of lanes, and median type. The bicycle and pedestrian LOS look-up tables provide maximum auto ser- vice volumes according to the percentage of sidewalk and bicycle lane coverage on the road segment. LOS Adjusted Service Frequency (vehicles per hour) A > 6.0 B 4.01 to 6.0 C 3.0 to 4.0 D 2.0 to 2.99 E 1.0 to 1.99 F < 1.0 Exhibit 15. FDOT Bus LOS Thresholds. Conditions that must be met Arterial Class Median Mid-Block Through Lanes Auto LOS CrossAdj I All situations 2 A or B 1.05 II All situations 2 A, B, or C 1.05 III All situations ≤ 4 A or B 1.05 IV All situations ≤ 4 All LOS 1.05 I None or non-restrictive ≥ 4 B-F 0.80 I Restrictive ≥ 8 All LOS 0.80 II None or non-restrictive ≥ 4 C-F 0.80 II Restrictive ≥ 8 All LOS 0.80 III None or non-restrictive ≥ 4 D-F 0.80 III Restrictive ≥ 8 All LOS 0.80 All cases not included above = 1.00 Exhibit 17. Roadway Crossing Adjustment Factors for Bus LOS (CrossAdj). Daily Hours of Service SpanAdj 19 – 24 1.15 17 – 18 1.05 14 – 16 1.00 12 – 13 0.90 4 – 11 0.75 0 – 3 0.55 Exhibit 16. Bus Span of Service Adjustment Factors for Bus LOS (SpanAdj).

10 LOS Score A < 1.5 B > 1.5 and < 2.5 C > 2.5 and < 3.5 D > 3.5 and < 4.5 E > 4.5 and < 5.5 F > 5.5 Exhibit 19. FDOT Bicycle and Pedestrian LOS Score Thresholds. Conceptual planning analysis evaluates urban street facility level of service on a segment by segment basis. The segment lev- els of service for auto and bus are averaged (weighted by length) to obtain a facility LOS for each mode. For pedestrians and bicycles, the facility LOS is the average of the segment LOS for the single worst segment of the facility and the length weighted average segment LOSs for all of the other segments of the facil- ity. The level of service at points (intersections) within the facil- ity is not taken into account in the estimation of facility LOS. Bicycle LOS Florida’s quality of service perspective is based on the bicyclists’ perspective of the safety of sharing the roadway en- vironment with motor vehicle traffic. This is based on the Bicycle LOS Model, originally developed by Sprinkle Con- sulting Inc. (SCI), and which has been applied to more than 200,000 miles of roadways in the United States (including throughout Florida) and Canada. In the Bicycle LOS Model, bicycle levels of service are based on five variables with rela- tive importance ordered (according to relative absolute value of “t” statistics) in the following list: • Average effective width of the outside through lane, • Motorized vehicle volumes, • Motorized vehicle speeds, • Heavy vehicle (truck) volumes, and • Pavement condition. Average effective width is largely determined by the width of the outside travel lane and [any attendant bicycle lane] striping, but also includes other factors such as the effects of on-street parking and drainage grates. Each of the variables is weighted by coefficients derived by stepwise regression mod- eling. A numerical LOS score, generally ranging from 0.5 to 6.5, is determined and stratified to a LOS letter grade. Thus, unlike the determination of automobile LOS in the HCM2000, in which there is usually only one service measure (e.g., average travel speed), bicycle LOS is determined based on multiple factors. The facility segment bicycle LOS score (BLOS) is estimated according to the following equation and the equivalent letter grade LOS is reported according to Exhibit 19. BLOS = 0.507 ln (Vol15/L) + 0.199SPt(1 + 10.38HV)2 + 7.066(1/PR5)2 − 0.005(We)2 + 0.760 (Eq. 3) Where BLOS = Bicycle level of service score ln = Natural log Vol15 = Directional motorized vehicle count in the peak 15 minute time period L = Total number of directional through lanes SPt = Effective speed factor = 1.1199 Ln(SPp − 20) + 0.8103 SPp = Posted speed limit (a surrogate for average running speed) HV = Percentage of heavy vehicles PR5 = FHWA’s five point pavement surface condition rating We = Average effective width of outside through lane Many of the factors in the Bicycle LOS Model equation are also used to determine automobile LOS in the HCM2000 methodology and are either logarithmic or exponential functions. Logarithmic and exponential functions make the importance of the variables differ significantly depending on the precise value. For example, the bicycle LOS drops dra- matically as motorized vehicle volumes initially rise, but then tends to deteriorate more slowly at higher volumes. Another example is the effect of motorized vehicle speed. At low speeds, the variable is not as significant in determining bicy- cle LOS, but at higher speeds it plays an ever-increasing role. Pedestrian LOS The pedestrian LOS model was developed for FDOT in a manner similar to that for the bicycle model. The pedestrian LOS model reflects the perspective of pedestrians sharing the roadside environment with motor vehicles and has been ap- plied to cities in Florida and elsewhere in the United States. Pedestrian levels of service are based on four variables in the following list: • Existence of a sidewalk, • Lateral separation of pedestrians from motorized vehicles, Pedestrian LOS Adjustment Factor A 1.15 B 1.10 C 1.05 D 1.00 E 0.80 F 0.55 Exhibit 18. Pedestrian LOS Adjustment Factors for Bus LOS (PLOSAdj).

11 Framework Objective HCM TCQSM FDOT Q/LOS 1. National Application Designed for Nation Designed for Nation Designed for State 2. LOS is Travelers’ Perspective Claimed, but no proof A blend of traveler and operator perspectives A blend of HCM, TCQS and traveler surveys 3. Applicable to Urban Streets Yes Yes Yes 4. Considers All factors within ROW Many factors considered, but not all Many factors considered, but not all Many factors considered, but not all 5. Safety and Economic Factors No No Perceived safety included 6. Comparable Modal LOS Uses speed for auto, bike, and pedestrian, but not transit Only considers transit Different LOS measures by mode 7. Modal Interactions Some but not all–See table below. Some but not all–See table below. Some but not all–See table below. 8. LOS Reflects All Movements Only Through Yes, all bus service on arterial is counted Only Through 9. No Averaging Across Modes Does not average Considers only single mode Does not average 10. Not Limited by HCM Limits Limited by HCM HCM limits not applicable Limited by HCM ROW = Right of Way HCM = Highway Capacity Manual LOS = Level of Service Exhibit 20. Evaluation of Major LOS Manuals Against NCHRP 3-70 Framework Objectives. • Motorized vehicle volumes, and • Motorized vehicle speeds. Each of the variables is weighted according to stepwise re- gression modeling: A numerical LOS score, generally ranging from 0.5 to 6.5, is determined along with the corresponding LOS letter grade. Thus, like the bicycle LOS approach (but unlike the automobile approach), pedestrian LOS is deter- mined based on multiple factors. In developing the pedestrian LOS Model, the researchers, SCI staff under contract with FDOT, conducted stepwise re- gression analyses using 1,315 real-time observations from a research effort conducted in 2000 in Pensacola, Florida. Many of the terms in the pedestrian LOS model equation are also used to determine automobile LOS in the HCM method- ology and bicycle LOS in the bicycle LOS model. The logarith- mic and exponential functions make the importance of the variables differ significantly depending on the precise value. The pedestrian LOS score (PLOS) is estimated according to the equation below. (This formula differs from the formula originally produced as part of the Pensacola survey. FDOT has retained the variables from the original survey but the co- efficients and constant have been changed. See Phillips, Karachepone, and Landis [9] for original PLOS equation.) The PLOS score is entered in the above table to obtain the equivalent LOS letter grade. PLOS = −1.2276 ln (Wol + Wl + fp × %OSP + fb × Wb + fsw × Ws) + 0.0091 (Vol15/L) + 0.0004 SPD2 + 6.0468 (Eq. 4) Where PLOS = Pedestrian level of service score Ln = Natural log Wol = Width of outside lane Wl = Width of shoulder or bicycle lane fp = On-street parking effect coefficient (=0.20) %OSP = Percent of segment with on-street parking fb = Buffer area barrier coefficient (=5.37 for trees spaced 20 feet on center) Wb = Buffer width (distance between edge of pavement and sidewalk, feet) fsw = Sidewalk presence coefficient (= 6 − 0.3Ws) Ws = Width of sidewalk Vol15 = Count of motorized vehicles in the peak 15 minute period L = Total number of directional through lanes SPD = Average running speed of motorized vehicle traffic (mi/hr) 2.2 Evaluation Against NCHRP 3-70 Framework Objectives This section evaluates the three major guidebooks on level of service against the NCHRP 3-70 objectives for a multi- modal level of service framework for urban streets. Exhibit 20 summarizes the conclusions. The following paragraphs ex- plain these conclusions in more detail. Highway Capacity Manual Exhibit 21 critiques the LOS criteria used in the Highway Capacity Manual. Exhibit 22 critiques the intermodal rela- tionships incorporated in the Highway Capacity Manual.

12 Auto Mean auto speed for through traffic Applies only to arterials, not collector or local streets Transit Hours of Daily Service, Reliability These are the two segment LOS criteria for availability and comfort/convenience Bicycle Mean speed of bicycle through traffic Applies only if designated bicycle lanes are present Pedestrian Mean speed of pedestrian through traffic Applies only if sidewalk is present Mode LOS Criterion Comments Mode Auto Transit Bicycle Pedestrian Auto Higher auto volumes reduce auto LOS. The effect cannot be computed. Higher auto volumes may reduce reliability, but no estimation method is available in the HCM. Higher auto volumes have no direct effect on span of transit service. Higher auto volumes indirectly affect bicycle LOS by affecting delays at signals. For signalized intersections, higher auto volumes indirectly affect pedestrian LOS by affecting delays at signals. For unsignalized intersections, higher auto volumes directly affect pedestrian delays and, therefore, pedestrian LOS. Transit Higher transit volumes reduce capacity and increase delays at signalized intersections The effect cannot be computed. Higher bus volumes may reduce reliability, but no effect on span of service. Higher transit volumes reduce capacity and increase delays at signalized intersections Higher transit volumes reduce capacity and increase delays at signalized intersections Bicycle Higher bicycle volumes reduce capacity and increase delays at signalized intersections The effect cannot be computed. Heavy bicycle volumes may reduce reliability, but no impact on span of service. Higher bicycle volumes reduce mean segment speed which reduces LOS (HCM Exhibit 19-3) Higher bicycle volumes have NO effect on walk speed or delay at signals. Pedestrian Higher pedestrian volumes reduce capacity and increase delays at signalized intersections The effect cannot be computed. Higher pedestrian flows may affect reliability but not span of service. Pedestrian flows between 1 and 60/hr. may indirectly affect bicycle LOS by affecting delays at signals. Higher volumes have NO effect. The effect is indirect except at unsignalized crossings where higher pedestrian flows affect the group critical gap and therefore pedestrian delay. Shaded boxes indicate weak or non-existent inter-relationships. No effect means that a change in modal volume has no effect on LOS as computed per the HCM. Exhibit 22. The Modal Operational Inter-Relationships in the HCM. Exhibit 21. HCM LOS Criteria for Urban Street. National Multimodal Application: The HCM is designed to be applied nationally for all four modes (i.e., auto, transit, bicycle, and pedestrian). Level of Service from a Traveler’s Perspective: The HCM claims to predict LOS from the traveler’s perspective, but there is little evidence to support this claim. The service meas- ures were developed in committee without specific research of traveler opinions to support the selected service measures. Applicable to Urban Streets: The HCM is designed to be applied to urban arterials where the through movement is the only function of the street. It may be less applicable to collec- tors where both through movement and access are important functions of the street. Considers All Factors Within Right of Way: The auto LOS methodology incorporates all geometric and signal op- eration factors considered relevant to the prediction of auto speed. The transit LOS method does not yet have a method- ology for incorporating the effects of signal operation, traffic flow, and other factors in the right of way that can influence bus service reliability. The pedestrian and bicycle LOS

13 methodologies incorporate the effects of intersections on av- erage pedestrian and bicycle speeds, but do not consider other potential factors (such as interference). Safety and Economic Factors: Safety and economic factors are not included in any of the LOS methodologies. Comparable Modal LOS: The HCM uses the same service measure, speed, to predict traveler LOS on urban streets for auto, bicycle, and pedestrians. Transit does not use speed for LOS at the urban street level. However the LOS thresholds for each mode were selected by committee and are not backed up by research indicating comparability of LOS values across modes. Modal Interactions: The HCM incorporates many but not all of the potential cross-modal influences on level of service. Exhibit 21 highlights the key LOS criteria for each mode. Exhibit 22 then shows how the various modes can affect each of these key LOS criteria. The HCM takes into account the effects of pedestrians, bi- cycles, and transit on auto delay at signalized intersections. The signalized intersection delay in turn affects the estimated mean speed of through traffic on the urban street. The mean speed is the LOS criterion for an urban street in the HCM. Higher auto volumes indirectly affect bicycle and pedes- trian LOS in the HCM method by affecting the signal timing at the intersections. Longer cycle lengths and longer red times would increase bicycle and pedestrian delay and reduce their level of service on the street. Higher auto volumes would indirectly affect transit relia- bility by increasing the probability of congestion, but the HCM provides no method for estimating this effect. Thus the effect of auto volumes on transit LOS cannot currently be accounted for using the available HCM procedures. The effects of pedestrians on bicycle level of service and the effects of bicycles on pedestrian level of service are accounted for in the analysis of off-street facilities, but not for on-street facilities in the HCM. Higher transit volumes, by reducing capacity and increas- ing congestion, can adversely affect bicycle and pedestrian LOS in the HCM method by affecting the cycle length and red times at signalized intersections. LOS Reflects All Movements: The HCM focuses on pre- dicting urban street LOS only for the through movement for auto, bicycle, and pedestrian. The transit LOS includes any service on the street and at each stop. Averaging LOS Across Modes: The HCM does not aver- age LOS across modes. HCM Limitations: The HCM lists nine conditions (p. 15-1) that are not accounted for in the current urban streets method- ology for auto LOS: 1. Presence or lack of on-street parking; 2. Driveway density or access control; 3. Lane additions leading up to or lane drops leading away from intersections; 4. The effects of grades between intersections; 5. Any capacity constraints between intersections (such as a narrow bridge); 6. Mid-block medians and two-way left-turn lanes; 7. Turning movements that exceed 20 percent of the total volume on the street; 8. Queues at one intersection backing up to and interfering with the operation of an upstream intersection; and 9. Cross-street congestion blocking through traffic. Transit TCQSM Critique Exhibit 23 critiques the intermodal relationships in the Transit Capacity and Quality of Service Manual. National Multimodal Application: The TCQSM is de- signed to be applied nationally for transit only. Level of Service from a Traveler’s Perspective: The TCQSM LOS measures are based on surveys that identified service factors important to traveler perceptions. The LOS E/F thresholds were set based on a project team/project panel consensus of undesirable service from a passenger stand- point; the other thresholds ideally represent points where a noticeable change in service quality occurs (e.g., when no more seats are left), and otherwise represent even ranges of the service measure between LOS A and LOS F. Applicable to Urban Streets: The TCQSM is oriented to the transit service features, not the street facility. LOS meas- ures are provided for stops, routes, and the system as a whole. The measures must be adapted for use on a specific street facility. Considers All Factors Within Right of Way: The TCQSM does not currently provide a methodology for taking into account the effects of street facility characteristics on transit LOS. Walk and drive accessibility are currently not included in bus stop level of service. No methodology is currently available for estimating the effect of traffic congestion and signal operation on transit service reliability. Safety and Economic Factors: Safety and economic factors are not included in the LOS methodology. Comparable Modal LOS: The TCQSM focuses on transit. The selected service measures are specific to transit and are not comparable with those for other modes. Modal Interactions: The TCQSM incorporates many but not all of the potential cross-modal influences on level of service. Exhibit 23 shows how the various modes can affect the key LOS criteria for transit. LOS Reflects All Movements: The transit LOS includes any service on the street and at each stop. Averaging LOS Across Modes: The TCQSM does not average LOS across modes.

14 Mode Auto Transit Bicycle Pedestrian Auto Not Applicable Higher auto volumes may reduce reliability, but no estimation method is available in the TCQSM. Reduced reliability affects passenger loads. Auto volumes, street width, and signal timing affect street crossing difficulty which can reduce service coverage. Higher auto volumes reduce bus speed, which affects tr ansit-auto travel time, but no estimation method is available in the HCM or TCQSM. Not Applicable Not Applicable Transit Not Applicable Higher bus volumes reduce bus speed, which affects transit-auto travel time. High bus volumes relative to bus capacity affect reliability, but no estimation method is available in the TCQSM. Not Applicable Not Applicable Bicycle Not Applicable No estimation method is available in the HCM or TCQSM for the effect of bikes on bus speed or reliability. Not Applicable Not Applicable Pedestrian Not Applicable Pedestrian crossing volumes affect right-turn capacity, which affects bus lane capacity, which affects bus travel time and reliability, but no estimation method is available in the TCQSM. Not Applicable Not Applicable Shaded boxes indicate weak or non-existent inter-relationships. No effect means that a change in modal volume has no effect on LOS as computed per the TCQSM. Exhibit 23. The Modal Operational Inter-Relationships in the TCQSM, Second Edition. Mode LOS Criterion Comments Auto Mean auto speed for through traffic Transit Frequency of Service Has modifiers for walk access and hours of service Bicycle Index Based on design and traffic volumes Pedestrian Index Based on design and traffic volumes Exhibit 24. FDOT LOS Criteria for Urban Street. HCM Limitations: The HCM limitations are irrelevant to the TCQSM. Florida DOT Q/LOS Handbook Exhibit 24 critiques the LOS criteria in the Florida DOT Q/LOS Handbook. Exhibit 25 critiques the intermodal rela- tionships in the Florida DOT Q/LOS Handbook. National Multimodal Application: The FDOT Q/LOS Handbook is designed to be applied statewide for all four modes (i.e., auto, transit, bicycle, and pedestrian). Level of Service from a Traveler’s Perspective: The Q/LOS Handbook is a blend of local research on bicycle/pedestrian perceptions of LOS and the two national manuals—the HCM and TCQSM. The Q/LOS Handbook thus shares some of the weaknesses of the national manuals. The HCM claim that auto LOS accurately reflects traveler perception has not been verified. The TCQSM transit LOS is a blend of traveler per- ceptions and transit operator objectives. The pedestrian and bicycle LOS measures have been experimentally verified against traveler perceptions. Applicable to Urban Streets: The FDOT Q/LOS Hand- book is designed to be applied to urban arterials where the through movement is the only function of the street. It may be less applicable to collectors where both through move- ment and access are important functions of the street. Considers All Factors Within Right-of-Way: Like the HCM, the FDOT Q/LOS Handbook auto LOS methodology incorporates all geometric and signal operation factors con- sidered relevant to the prediction of auto speed. The transit LOS method does not yet have a methodology for incorpo- rating the effects of signal operation, traffic flow, and other factors in the right-of-way that can influence bus service reli- ability. The pedestrian and bicycle LOS methodologies incorporate all factors related to the right-of-way that were found to significantly affect perceived LOS. Safety and Economic Factors: Economic factors are not in- cluded in any of the LOS methodologies. Perceived safety is an underlying factor in the pedestrian and bicycle LOS methods. Comparable Modal LOS: The FDOT Q/LOS Handbook measures for pedestrian and bicycle modes are probably comparable in terms of their measurement of degree of sat- isfaction, but no actual tests of this conjecture have been performed. The auto and transit LOS measures are gener- ally not comparable with the pedestrian and bicycle LOS measures.

15 Mode Auto Transit Bicycle Pedestrian Auto Higher auto volumes reduce auto LOS Higher auto flows have NO effect on transit frequency, span of service, or walk access Higher auto volumes and/or higher speeds reduce bicycle LOS Higher auto volumes and/or higher speeds reduce pedestrian LOS Transit Higher transit volumes reduce capacity and increase delays at signalized intersections Higher bus volumes mean higher frequencies, which increases transit LOS Higher heavy vehicle volumes reduce bicycle LOS Higher heavy vehicle volumes reduce pedestrian LOS Bicycle Higher bicycle volumes reduce capacity and increase delays at signalized intersections Higher bike flows have NO effect on transit frequency, span of service, or walk access barriers Higher bicycle volumes have NO effect on BLOS. Better design affects BLOS. Higher bicycle volumes have NO effect on PLOS. Better bike design may affect PLOS. Pedestrian Higher pedestrian volumes reduce capacity and increase delays at intersections Higher pedestrian volumes have NO effect on transit LOS. Better pedestrian facilities improve transit LOS. Higher pedestrian volumes have NO effect on BLOS. Better pedestrian design may affect PLOS. Higher pedestrian volumes have NO effect on PLOS. Better design affects PLOS. Shaded boxes indicate weak or non-existent inter-relationships. No effect means that a change in modal volume has no effect on LOS as computed per FDOT. Exhibit 25. The Modal Operational Inter-Relationships in the FDOT Q/LOS Handbook. Modal Interactions: The FDOT Q/LOS Handbook incor- porates many but not all of the potential cross-modal influ- ences on level of service. Exhibit 24 highlights the key LOS criteria for each mode. Exhibit 25 shows how the various modes can affect each of these key LOS criteria. 2.3 Conclusions Current Agency Practices Public agencies make extensive use of the Highway Capacity Manual and the Florida Quality/Level of Service Handbook for planning and designing urban streets. The Transit Capacity and Quality of Service Manual is a recent de- velopment and has not yet seen extensive adoption by pub- lic agencies. Level of service is used on a daily basis in most public agen- cies to assess the adequacy of the design of urban streets, to assess the effects of new development on urban street opera- tions, and to identify the appropriate mitigation measures for new development. These analyses however focus primarily on auto level of service. The survey of current agency practices found little actual use of level of service for the planning or design of urban streets for transit, bicycle, and pedestrian modes, except in the State of Florida where it is a recent development. There is, however, a great deal of interest among public agencies in acquiring the ability to estimate and forecast level of service for all four modes, especially if the issue of comparability of results across modes can be achieved. The Major Level of Service Manuals The existing LOS frameworks outlined in the major LOS manuals generally do not provide comparable LOS results across modes. This is due to different definitions of level of service and different measurement scales used by the various manuals for each mode: 1. The HCM Urban Street LOS measures are not based on surveys of traveler satisfaction and thus cannot be com- pared with the traveler satisfaction based LOS measures contained in the TCQSM and FDOT manuals. 2. The TCQSM provides no single LOS result for transit but several different dimensions of LOS making mode-to- mode comparisons difficult. The TCQSM LOS measures are derived from surveys of traveler satisfaction. 3. The FDOT multimodal framework, because it relies on the HCM and TCQSM manuals for auto and transit, suf- fers from the same comparability limitations as those manuals. The auto LOS in particular is not comparable with the bike and pedestrian LOS scales, because they are based on different dimensions of perceived and measured traveler satisfaction. The major existing LOS manuals are spotty in their incor- poration of known modal interactions on modal LOS. Either the selected modal LOS measure (such as hours of bus ser- vice) is insensitive to the effects of other modes or an accepted methodology has not yet been established for predicting the intermodal effects.

16 The Florida bicycle and pedestrian level of service models have a strong scientific basis, but their incorporation in the national manuals has been hindered by the perception (valid or not) that they are based strictly on data from a single city in a single state, even though they have been applied in many jurisdictions around the United States. There are also con- cerns at the national level (valid or not) that the level of serv- ice measured in Florida for bicycles and pedestrians is a different dimension of traveler satisfaction not related to traditional traffic operations analysis and, therefore, incom- patible with the national manuals. Implications for Research Project The major issues for establishing a multimodal level of service framework are as follows: 1. Establishing comparability of meanings for LOS grades across modes, 2. Establishing models for predicting LOS that reflect the in- teractions among modes in an urban street setting, and 3. Establishing a credible national basis for the multimodal LOS framework and models.

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Multimodal Level of Service Analysis for Urban Streets Get This Book
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TRB’s National Cooperative Highway Research Program (NCHRP) Report 616: Multimodal Level of Service Analysis for Urban Streets explores a method for assessing how well an urban street serves the needs of all of its users. The method for evaluating the multimodal level of service (MMLOS) estimates the auto, bus, bicycle, and pedestrian level of service on an urban street using a combination of readily available data and data normally gathered by an agency to assess auto and transit level of service. The MMLOS user’s guide was published as NCHRP Web-Only Document 128.

Errata

In the printed version of the report, equations 36 (pedestrian segment LOS) and 37 (pedestrian LOS for signalized intersections) on page 88 have been revised and are available online. The equations in the electronic (dpf) version of the report are correct.

In June 2010, TRB released NCHRP Web-Only Document 158: Field Test Results of the Multimodal Level of Service Analysis for Urban Streets (MMLOS) that explores the result of a field test of the MMLOS in 10 metropolitan areas in the United States.

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