3 Presentation Outlines: IntroductionPedestrian Capacity TerminologyPrinciples of Pedestrian FlowPedestrian Walking SpeedPerformance MeasuresLevel of serviceDetermining Effective Walkway WidthInterrupted-Flow Pedestrian Facilitiessignalized IntersectionsUnsignalized IntersectionsCase study
4 Introduction:The qualitative measures of pedestrian flow are similar to those used for vehicular, such as the freedom to choose desired speeds and to bypass others. Other measures flow related specifically to pedestrian flow include :the ability to cross a pedestrian traffic stream, to maneuver generally without conflicts and changes in walking speed.the delay experienced by pedestrians at signalized and unsignalized intersections.Safety is provided by the separation of pedestrians from vehicular traffic on the same horizontal and vertical plane.Traffic control devices can provide time separation between pedestrian and vehicular traffic.
5 Pedestrian Capacity Terminology The following are important terms used for pedestrian facility capacity and LOS:Pedestrian speed is the average pedestrian walking speed, generally expressed in units of meters per second.Pedestrian flow rate is the number of pedestrians passing a point per unit of time, expressed as pedestrians per 15 min or pedestrians per minute.Pedestrian flow per unit of width is the average flow of pedestrians per unit of effective walkway width, expressed as pedestrians per minute per meter (p/min/m).Pedestrian density is the average number of pedestrians per unit of area within a walkway or queuing area, expressed as pedestrians per square meter (p/m2).Pedestrian space is the average area provided for each pedestrian in a walkway or queuing area, expressed in terms of( m2/P).Platoon refers to a number of pedestrians walking together in a group, usually involuntarily, as a result of signal control and other factors.
6 Principles of Pedestrian Flow Pedestrian Speed-Density RelationshipsThe fundamental relationship between speed, density, and volume for pedestrian flow is analogous to vehicular flow. As volume and density increase, pedestrian speed declines.
7 v ped = Sped *Dped Flow-Density Relationships The relationship among density, speed, and flow for pedestrians is similar to that for vehicular traffic streams, and is expressed in this Equationv ped = Sped *Dpedwherevped = unit flow rate (p/min/m),Sped = pedestrian speed (m/min), andDped = pedestrian density (p/m2).or space, as follows:whereM = pedestrian space (m2/p).
8 PEDESTRIAN SPACE REQUIREMENTS A simplified body ellipse of 0.50 m x 0.60 m, with total area of 0.30 m2 is used as the basic space for a single pedestrian. This represents the practical minimum for standing pedestrians. In evaluating a pedestrian facility, an area of 0.75 m2 is used as the buffer zone for each pedestrian.PEDESTRIAN WALKING SPEEDPedestrians exhibit a wide range of walking speeds, varying from 0.8 m/s to 1.8 m/s.If 0 to 20 percent of pedestrians are elderly, the average walking speed is 1.2 m/s on walkways.If elderly people constitute more than 20 percent of the total pedestrians, the average walking speed decreases to 1.0 m/s.On sidewalks, the free-flow speed of pedestrians is approximately 1.5 m/s .Design pedestrian speed = 1.22 m/s( speed = distance/ Time = 2.43/2 = 1.2 2m/s.)
9 PERFORMANCE MEASURESCROSS-FLOW TRAFFIC: PROBABILITY OF CONFLICT
10 Level of service :PEDESTRIAN WALKWAY LOS LOS A: Pedestrian Space > 5.6 m2/p Flow Rate ≤ 16 p/min/mLOS B:Pedestrian Space > 3.7–5.6 m2/p Flow Rate > 16–23 p/min/mLOS C:Pedestrian Space > 2.2–3.7 m2/p Flow Rate > 23–33 p/min/m
11 Level of service PEDESTRIAN WALKWAY LOS: LOS D: Pedestrian Space > 1.4–2.2 m2/p Flow Rate > 33–49 p/min/mLOS E:Pedestrian Space > 0.75–1.4 m2/p Flow Rate > 49–75 p/min/mLOS F:Pedestrian Space ≤ 0.75 m2/p Flow Rate varies p/min/m
12 Level of service QUEUING AREA LOS(with standing pedestrians) LOS A Average Pedestrian Space > 1.2 m2/pLOS BAverage Pedestrian Space > 0.9–1.2 m2/ pLOS CAverage Pedestrian Space > 0.6–0.9 m2/p
13 Level of service QUEUING AREA LOS(with standing pedestrians) LOS D Average Pedestrian Space > 0.3–0.6 m2/pLOS EAverage Pedestrian Space > 0.2–0.3 m2/pLOS FAverage Pedestrian Space ≤ 0.2 m2/p
14 REQUIRED INPUT DATA AND ESTIMATED VALUES Length of Sidewalk: The length of a sidewalk can be approximately equal to the length of an urban street.Effective Width
15 Street Corner RadiusThe street corner radius depends on several factors, including:the speed of vehicles,the angle of the intersection,the types of vehicles in the turning volume, andright-of-way limitations on the connecting sidewalks.
16 DETERMINING EFFECTIVE WALKWAY WIDTH Effective walkway width is the portion of a walkway that can be used effectively by pedestrians.WE = WT – WowhereWE = effective walkway width (m),WT = total walkway width (m), andWo = sum of widths and shy distances from obstructions on the walkway (m).
18 INTERRUPTED-FLOW PEDESTRIAN FACILITIES 1) Signalized IntersectionsThe signalized intersection crossing is more complicated to analyze than a midblock crossing, because :it involves intersecting sidewalk flows,pedestrians crossing the street, andothers queued waiting for the signal to change.
19 average pedestrian delay when pedestrian flow rates reach 5,000 p/h . The average delay per pedestrian for a crosswalk is given by this Equationwheredp = average pedestrian delay (s),g = effective green time (for pedestrians) (s), andC = cycle length (s).
20 Pedestrian Area Requirements at Street Corners There are two types of pedestrian area requirements at street cornersa) circulation area:is needed to accommodate pedestrians crossing during the green signal phase, those moving to join the red-phase queue, and those moving between the adjoining sidewalks but not crossing the street.b) hold area:is needed to accommodate pedestrians waiting during the red signal phase.
22 The following Exhibits shows the signal phase conditions analyzed in corner and crosswalk computations.Condition 1: is the minor-street crossing phase during the major-street green, with pedestrians queuing on the major-street side during the minor-street red phase.
23 Condition 2: is the major-street crossing phase, with pedestrians crossing during the minor-street green, and queuing on the minor-street side during the major-street red phase.
24 Determining Street Corner Time-Space Available Time-SpaceThe total time-space available for circulation and queuing in the intersection corner during an analysis period is the product of the net corner area and the length of the analysis period (one signal cycle).TS = C(WaWb − 0.215R2)whereTS = available time-space (m2-s),Wa = effective width of Sidewalk a (m),Wb = effective width of Sidewalk b (m),R = radius of corner curb (m), andC = cycle length (s).
25 Holding-Area Waiting Times For Condition 1(major street), the following equation is used to compute holding-area waiting time.whereQtdo = total time spent by pedestrians waiting to cross the major street during one cycle (p-s);Vdo = the number of pedestrians waiting to cross the major street during one cycle,Rmi= the minor-street red phase, or the Don't Walk phase if there are pedestrian signals (s);C = cycle length (s).Note: For condition 2 we can use the same equation by replaced symbols in this equation by the symbols related to minor street
26 Determining Circulation Time-Space The net corner time-space available for circulating pedestrians is the total available time-space minus the time-space occupied by the pedestrians waiting to cross.TSc = TS − 0.5(Qtdo + Qtco )whereTSc = total time-space available for circulating pedestrians (m2-s),TS = total time-space available (m2-s),Qtdo = total time spent by pedestrians waiting to cross the major street during one cycle (p-s),Qtco = total time spent by pedestrians waiting to cross the minor street during one cycle (p-s).
27 Determining Crosswalk Time-Space Time-space of a crosswalk at a street corner is computed according to this EquationwhereTS = time-space (m2-s);L = crosswalk length (m);WE = effective crosswalk width (m);WALK + FDW = effective pedestrian green time on crosswalk (s);Sp = average speed of pedestrians (m/s); andG = green time for phase, if WALK + FDW is not installed (s).
28 Total crossing time or effective green time required to clear an intersection crossing is computed according to this Equation:wheret = total crossing time (s),L = crosswalk length (m),Sp = average speed of pedestrians (m/s),Nped = number of pedestrians crossing during an interval (p),W = crosswalk width (m), and3.2 = pedestrian start-up time (s).
29 2) Unsignalized Intersections critical gap : is the time in seconds below which a pedestrian will not attempt to begin crossing the street.For a single pedestrian, critical gap is computed according to this Equationtc: critical gap for a single pedestrian (s),Sp : average pedestrian walking speed (m/s),L = crosswalk length (m), andts= pedestrian start-up time and end clearance time (s).
30 If platooning is observed in the field, then the spatial distribution of pedestrians should be computed using below Equation, to determine group critical gap, If no platooning is observed, spatial distribution of pedestrians is assumed to be 1.WhereNp = spatial distribution of pedestrians (p),Nc = total number of pedestrians in the crossing platoon (p),WE = = effective crosswalk width (m), and0.75 = default clear effective width used by a single pedestrian to avoid interference when passing other pedestrians.
31 Nc = size of a typical pedestrian crossing platoon (p), To compute spatial distribution, the analyst must observe in the field or estimate the platoon size using the following EquationWhereNc = size of a typical pedestrian crossing platoon (p),Vp = pedestrian flow rate (p/s),V = vehicular flow rate (veh/s), andts = single pedestrian critical gap (s).
32 Group critical gap is determined using the following Equation wheretG = group critical gap (s),tc = critical gap for a single pedestrian (s), andNp = spatial distribution of pedestrians (p).The average delay per pedestrian for a crosswalk is given by this Equationwheredp = average pedestrian delay (s),v = vehicular flow rate (veh/s), andtG = group critical gap
33 Case studyThis study was done in 2011, where we get this information from graduation Project entitled "Evaluation and design of pedestrian facilities of traffic and engineering in the universities area and the intersection of the Saraya", including this study, process evaluation and design of sidewalks and crosswalk in this areas.
34 The following graph illustrates the behavior and the movement of pedestrians in Al-Azhar intersection.
36 pedestrians on the sidewalk+ pedestrians on the street 1)Sidewalkspedestrians on the sidewalk+ pedestrians on the streetsw1+sw1-sw2+sw2-sw3+sw3-sw4+sw4-sw5+sw5-sw6+sw6-sw7+sw7-sw8+sw8-12:00-12:1510359526154749784016312:15-12:301146321579155518912:30-12:451461054132001117205117212:45-01:0011862291156533634414501:00-01:15207255223983475418501:15-01:3012635266244804312001:30-01:4511538213229773373711301:45-02:0017819886371117
37 Sidewalk (A):Total width = 5.7 mWidth Preempted (There is unpaved portion = 2.70 m from the sidewalk display, panel guiding distance of 0.75 m from the edge of the pavement).Effective width = = 2.25Flow rate of pedestrians (sw5+sw5-) = 111 ped/15 minpedestrian unit flow rate = 111÷ (15 * 2.25) = 4 ped/min/m.LOS A
38 Passing on the crosswalk+ Passing outside of the crosswalk Pedestrians crosswalksTable below The sum of pedestrians who Passing crosswalk (R) and pedestrian Passing outside of the crosswalk (R-).Passing on the crosswalk+ Passing outside of the crosswalkR1+R1-R2+R2-R3+R3-R4+R4-R5+R5-R6+R6-R7+R7-R8+R8-12:00-12:154036153169130115546512:15-12:304738159179109132586712:30-12:454637222249123103778112:45-01:0035271501657576685001:00-01:15332519220989799601:15-01:30292221769647001:30-01:454820422961829101:45-02:00514221223778
39 Crosswalk (A-):Effective width = Total width = 4 m.Flow rate of pedestrians (R5+R5-) = 132 ped/15 minpedestrian unit flow rate= 132÷(15* 4) = 2 ped/min/m. < 16LOS AAssume cycle time = 120 sec.Time permitted to enter the pedestrians = 120 ÷ 4 = 30 sec.Length of crosswalk = width of road = 21 m.Time = distance ÷ speed = 21 ÷ 1.22 = 17.2 seconds = 18 seconds
40 1st Group = 18 seconds. 2nd Group = 18 +2 = 20 seconds 1st Group = 18 seconds. 2nd Group = = 20 seconds. 3rd Group = = 22 seconds 4th Group = = 24 seconds 5th Group = = 26 seconds 6th Group = = 28 seconds 7th Group = = 30 secondsFlow rate / min = 132 ÷ 15 = 9 person / min. Flow rate / cycle = 9 × 2 = 18 person / cycle time. Each group = flow rate / cycle time ÷ number of groups = 18 ÷ 7 = 2.57 = 3 person / group. Effective width = number of persons / group × width of person = 3 × 0.95 = 2.85mExisting width = 4 m > Effective widthWidth is adequate