Prepared byOsama Tabash

Khaled El-Yazory

Supervised byDr. Essam

Almasri

PEDESTRIANS

Presentation Outlines:Introduction Pedestrian Capacity TerminologyPrinciples of Pedestrian FlowPedestrian Walking SpeedPerformance MeasuresLevel of serviceDetermining Effective Walkway WidthInterrupted-Flow Pedestrian Facilitiessignalized IntersectionsUnsignalized IntersectionsCase study

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.

Pedestrian Capacity TerminologyThe 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.

Principles of Pedestrian FlowPedestrian Speed-Density Relationships

The fundamental relationship between speed, density, and volume for pedestrian flow is analogous to vehicular flow. As volume and density increase, pedestrian speed declines.

Flow-Density RelationshipsThe relationship among density, speed, and flow for pedestrians is similar to that for vehicular traffic streams, and is expressed in this Equation

v ped = Sped *Dped

wherevped = 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).

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.)

PERFORMANCE MEASURES

CROSS-FLOW TRAFFIC: PROBABILITY OF CONFLICT

Level of service:PEDESTRIAN WALKWAY

LOSLOS A:Pedestrian Space > 5.6 m2/p Flow Rate ≤ 16 p/min/m

LOS C:Pedestrian Space > 2.2–3.7 m2/p Flow Rate > 23–33 p/min/m

LOS B:Pedestrian Space > 3.7–5.6 m2/p Flow Rate > 16–23 p/min/m

Level of service

LOS D:Pedestrian Space > 1.4–2.2 m2/p Flow Rate > 33–49 p/min/m

LOS F:Pedestrian Space ≤ 0.75 m2/p Flow Rate varies p/min/m

LOS E:Pedestrian Space > 0.75–1.4 m2/p Flow Rate > 49–75 p/min/m

PEDESTRIAN WALKWAY LOS:

Level of serviceQUEUING AREA LOS(with standing pedestrians)

LOS AAverage Pedestrian Space > 1.2 m2/p

LOS C Average Pedestrian Space > 0.6–0.9 m2/p

LOS BAverage Pedestrian Space > 0.9–1.2 m2/ p

Level of serviceQUEUING AREA LOS(with standing pedestrians) LOS D

Average Pedestrian Space > 0.3–0.6 m2/p

LOS F Average Pedestrian Space ≤ 0.2 m2/p

LOS E Average Pedestrian Space > 0.2–0.3 m2/p

REQUIRED INPUT DATA AND ESTIMATED VALUESLength of Sidewalk: The length of a sidewalk can be approximately equal to the length of an urban street.

Effective Width

Street Corner Radius

The 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, and right-of-way limitations on the connecting sidewalks.

DETERMINING EFFECTIVE WALKWAY WIDTH

Effective walkway width is the portion of a walkway that can be used effectively by pedestrians.

WE = WT – Wo

whereWE = effective walkway width (m),WT = total walkway width (m), andWo = sum of widths and shy distances from obstructions on the walkway (m).

INTERRUPTED-FLOW PEDESTRIAN FACILITIES

1 )Signalized Intersections

The signalized intersection crossing is more complicated to analyze than a midblock crossing, because : it involves intersecting sidewalk flows, pedestrians crossing the street, and others queued waiting for the signal to change.

average pedestrian delay when pedestrian flow rates reach 5,000 p/h . The average delay per pedestrian for a crosswalk is given by this Equation

wheredp = average pedestrian delay (s),g = effective green time (for pedestrians) (s), andC = cycle length (s).

Pedestrian Area Requirements at Street Corners

There are two types of pedestrian area requirements at street corners

a) 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.

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.

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.

Determining Street Corner Time-SpaceAvailable 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).

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

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).

Determining Crosswalk Time-SpaceTime-space of a crosswalk at a street corner is computed according to this Equation

whereTS = 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).

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).

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 Equation

tc: 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).

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), and

0.75 = default clear effective width used by a single pedestrian to avoid interference when passing other pedestrians.

To compute spatial distribution, the analyst must observe in the field or estimate the platoon size using the following Equation

WhereNc = 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).

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 Equation

wheredp = average pedestrian delay (s),v = vehicular flow rate (veh/s), andtG = group critical gap

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.

The following graph illustrates the behavior and the movement of pedestrians in Al-Azhar intersection.

1)Sidewalks

 

pedestrians on the sidewalk+ pedestrians on the street

sw1+sw1- sw2+sw2- sw3+sw3- sw4+sw4- sw5+sw5- sw6+sw6- sw7+sw7- sw8+sw8-

12:00-12:15103 59 526 154 74 978 40 163

12:15-12:30114 40 632 157 91 555 40 189

12:30-12:45146 105 413 200 111 720 51 172

12:45-01:00118 62 291 156 53 363 44 145

01:00-01:15207 105 255 223 98 347 54 185

01:15-01:30126 35 266 244 80 347 43 120

01:30-01:45115 38 213 229 77 337 37 113

01:45-02:00178 74 223 198 86 371 53 117

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 = 5.7-2.7-0.75 = 2.25Flow rate of pedestrians (sw5+sw5-) = 111 ped/15 minpedestrian unit flow rate = 111÷ (15 * 2.25) = 4 ped/min/m.LOS A

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 crosswalk

R1+R1- R2+R2- R3+R3- R4+R4- R5+R5- R6+R6- R7+R7- R8+R8-

12:00-12:1540 36 153 169 130 115 54 65

12:15-12:3047 38 159 179 109 132 58 67

12:30-12:4546 37 222 249 123 103 77 81

12:45-01:0035 27 150 165 75 76 68 50

01:00-01:1533 25 192 209 89 79 96 96

01:15-01:3029 22 192 217 67 69 64 70

01:30-01:4548 37 204 229 65 61 82 91

01:45-02:0051 42 212 237 76 67 77 78

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

1st Group = 18 seconds.2nd Group = 18 +2 = 20 seconds.3rd Group = 20 +2 = 22 seconds4th Group = 22 +2 = 24 seconds5th Group = 24 +2 = 26 seconds6th Group = 26 +2 = 28 seconds7th Group = 28 +2 = 30 seconds

Flow 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 = 2.85m

Existing width = 4 m > Effective widthWidth is adequate

Thank You for attention