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Pedestrian Simulation for Urban Traffic Scenarios

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Jörg Dallmeyer<br />

Goethe University Frankfurt<br />

P.O. Box 11 19 32<br />

60054 Frankfurt, Germany<br />

dallmeyer@cs.uni-frankfurt.de<br />

<strong>Pedestrian</strong> <strong>Simulation</strong> <strong>for</strong> <strong>Urban</strong> <strong>Traffic</strong> <strong>Scenarios</strong><br />

Keywords: <strong>Pedestrian</strong> <strong>Simulation</strong>, <strong>Traffic</strong> <strong>Simulation</strong>, <strong>Urban</strong><br />

<strong>Scenarios</strong>, GIS<br />

Abstract<br />

<strong>Simulation</strong>s are widely used <strong>for</strong> modeling, analysis, planning,<br />

and optimization of traffic flows and phenomena. Every human<br />

moving in a city participates at least to some extent as<br />

a pedestrian in urban traffic. Nevertheless, pedestrians usually<br />

are not part of traffic simulations. This work presents a<br />

model <strong>for</strong> pedestrian movement, taking into account interactions<br />

with other road users and among pedestrians on pedestrian<br />

crossings. The components of the model are evaluated<br />

separately and in a city scenario with an accumulated road<br />

length of about 550km. Experimental results indicate an influence<br />

of pedestrians on urban traffic. This leads to the finding,<br />

that the consideration of pedestrians in urban traffic simulation<br />

may lead to a gain of knowledge.<br />

1 INTRODUCTION<br />

A continuously growing amount of road users leads to the<br />

need <strong>for</strong> traffic simulation in order to understand phenomena<br />

of traffic jam <strong>for</strong>mation and to find ways to increase traffic<br />

flow. <strong>Traffic</strong> is well understood <strong>for</strong> freeway scenarios.<br />

<strong>Urban</strong> traffic comprehends more heterogeneous road users<br />

like, e.g., cars, bicycles and pedestrians. <strong>Pedestrian</strong> simulation<br />

has gained more attention in the last years. There are high<br />

fidelity models like the social <strong>for</strong>ce model [7], macroscopic<br />

models like [8] or microscopic models built on cellular automatons<br />

like [1].<br />

Different types of models are used <strong>for</strong> different scenarios,<br />

e.g., optimization of traffic light green times <strong>for</strong> pedestrians,<br />

regulation of pedestrian flows at railway stations, or evacuation<br />

and panic scenarios <strong>for</strong> pedestrian safety.<br />

The focus of this work is the integration of pedestrians into<br />

the simulation system MAINS 2 IM (MultimodAl INnercity<br />

SIMulation) [3, 12] in order to study the impact of pedestrians<br />

on urban traffic. Thus, a model taking account of realistic<br />

pedestrian velocities and road crossing behavior has to<br />

be found. The model needs to be computationally efficient in<br />

time and space in order to simulate a whole city. To the best<br />

of our knowledge, such a model does not exist.<br />

The paper is structured as follows: Section 2 describes the<br />

traffic simulation system <strong>for</strong> urban multimodal traffic. Section<br />

Andreas D. Lattner<br />

Goethe University Frankfurt<br />

P.O. Box 11 19 32<br />

60054 Frankfurt, Germany<br />

lattner@cs.uni-frankfurt.de<br />

Ingo J. Timm<br />

University of Trier<br />

54296 Trier, Germany<br />

ingo.timm@uni-trier.de<br />

3 discusses related works, dealing with pedestrian behavior in<br />

order to build a new model (section 4). The model is examined<br />

in section 5. Section 6 discusses the influence of pedestrians<br />

on urban traffic in the simulation system. This work<br />

concludes with a short summary and a discussion of potential<br />

future investigations in section 7.<br />

2 SIMULATION SYSTEM<br />

The pedestrian model developed in this work is part of the<br />

traffic simulation system MAINS 2 IM <strong>for</strong> urban traffic scenarios<br />

under consideration of multimodal traffic. The system<br />

deals with cartographical material from OpenStreetMap 1 . A<br />

user-defined area can be extracted from an OpenStreetMap<br />

(.osm) file. Then, the geoin<strong>for</strong>mation is split into several layers<br />

in order to group the in<strong>for</strong>mation logically. The system<br />

generates a simulation graph with roads represented by objects<br />

of the data structure EdgeIn<strong>for</strong>mation (EI), connected<br />

by objects of NodeIn<strong>for</strong>mation (NI). This is done<br />

with help of a geographical in<strong>for</strong>mation system (GIS) on basis<br />

of GeoTools 2 . A number of analysis steps (e.g., finding<br />

roundabouts, bus routes, pedestrian crossings, traffic lights<br />

and much more) and correction steps (e.g., putting NIs at intersections<br />

and consider bridges and tunnels) are per<strong>for</strong>med<br />

afterwards in order to compute a valid graph.<br />

Multimodal traffic simulation is done with help of three basic<br />

traffic models <strong>for</strong> cars (passenger cars, trucks, and buses),<br />

bicycles and pedestrians. The models are continuous in space<br />

and discrete in time with a time step of one second per simulation<br />

iteration. A control module calls the update methods<br />

of each simulated traffic participant once per simulation iteration,<br />

i.e., once per simulated second.<br />

The simulation system is written in Java and runs on a PC.<br />

More detailed descriptions of the construction of the simulation<br />

system and the developed models <strong>for</strong> cars and bicycles<br />

can be found in [3, 4] and on http://www.mainsim.eu.<br />

This work deals with the developed model <strong>for</strong> pedestrian<br />

movement. There<strong>for</strong>e, an introduction to real world pedestrian<br />

behavior and pedestrian simulation is provided in the<br />

next section.<br />

1 http://www.openstreetmap.org<br />

2 http://www.geotools.org


3 PEDESTRIANS IN URBAN TRAFFIC<br />

<strong>Pedestrian</strong> behavior with regard to the interplay between<br />

road users and pedestrians is dependent on walking velocities<br />

of pedestrians and the road crossing behavior. This section<br />

discusses relevant literature in this field.<br />

The modeling of pedestrians <strong>for</strong> simulation of road networks<br />

has been discussed in [10], proposing a model based<br />

on the vehicle model of VISSIM [15]. The work has the focus<br />

of creating a model with realistic flow-velocity-density<br />

relationships. The shortcoming of this approach is the lack of<br />

two-way traffic, which is important <strong>for</strong> pedestrians.<br />

Different studies on pedestrian walking velocities have<br />

been per<strong>for</strong>med. A review is provided in [11]; in the following<br />

we briefly summarize the most important insights. A<br />

pedestrian p chooses velocity vp with respect to its physical<br />

constitution and whether p walks on a sidewalk or crosses<br />

a road. Crossing velocity is dependent on whether p is crossing<br />

with or without right of way. Additionally, aggressiveness<br />

increases velocity. This is modeled with help of an aggressiveness<br />

factor AF. These major findings have been derived<br />

from several studies monitoring different inner city crossings<br />

at different places [11].<br />

When p attempts to cross a road and is not able to do so due<br />

to road traffic, aggressiveness of p increases. Aggressiveness<br />

affects the walking velocity increasingly, when p finally is<br />

able to cross the road. Referring to [9], this may result in a<br />

maximum velocity increment of 0.5m · s −1 .<br />

The lowest velocities are walked on sidewalks. When<br />

crossing a road, pedestrians tend to speed up. The more hazardous,<br />

the faster. When crossing with right of way, pedestrians<br />

are slower than without right of way. The slowest crossing<br />

velocities are walked on crosswalks. At pedestrian lights, the<br />

waiting time until p is able to cross, increases aggressiveness<br />

and thus velocity.<br />

Each of these cases has to be separated with respect to<br />

the physical constitution of p. Men are slightly faster than<br />

women. The elderly are slower than adults and children. Finally,<br />

different localities lead to different velocities [11].<br />

When a pedestrian p decides to cross a road, p determines<br />

the estimated crossing time [13]<br />

ECT = w<br />

+ AF (1)<br />

vp<br />

where w is the width of the road. The distribution of ECT<br />

among pedestrians has been investigated in [2]. A mean ECT<br />

of ECT ≈ 7s at a road with w = 9.1m and a mean velocity<br />

of v = 1.2m · s −1 leads to a mean AF of AF ≈ −0.58s. This<br />

means, that pedestrians tend to underestimate the time needed<br />

to cross a road.<br />

These findings build the basis <strong>for</strong> our model of pedestrian<br />

movements.<br />

Figure 1. Positioning of pedestrian way objects on intersections.<br />

4 PEDESTRIAN MODEL<br />

The interaction between road users and pedestrians is one<br />

of the central aspects of this work. At first, pedestrians need<br />

to find their way through the simulation graph (subsection<br />

4.1). Interaction with road users will only take place, when<br />

pedestrians cross roads. Thus, a mesoscopic simulation model<br />

<strong>for</strong> pedestrians is introduced in this section. It consists of one<br />

model <strong>for</strong> sidewalk movements (subsection 4.2) and another<br />

model <strong>for</strong> crossing roads at pedestrian crossings (subsection<br />

4.3).<br />

4.1 Routing<br />

The calculation of fastest ways in a graph data structure is a<br />

well known problem. In this work, precalculated routes from<br />

each NIa to each NIb can be used as well as online calculated<br />

routes with help of the A* search algorithm and a probabilitybased<br />

routing mechanism [3]. The result of each algorithm is<br />

a list of EIs and a list of NIs, defining the route to be walked.<br />

In the beginning, it is randomly chosen, which side of the<br />

road a pedestrian stands on. Then, a heuristic algorithm calculates<br />

where to cross the roads during the walk through the<br />

calculated route. Crossing can be done on EIs if there is a sufficient<br />

gap. Additionally, NIs store pedestrian ways, allowing<br />

<strong>for</strong> crossing and pedestrian interaction. Figure 1 shows an intersection.<br />

NI is connected to three EIs : EI1...EI3. Each<br />

dashed line shows the position of a pedestrian way.<br />

A pedestrian has to cross a road, e.g., whenever the following<br />

EI is connected to the current EI into a direction which<br />

is oppositely to the side of the road of the pedestrian. The<br />

pedestrian plan of road crossings privileges pedestrian crossings<br />

and traffic lights (both stored in NIs) over crossing the<br />

road without right of way. Additionally, NIs are used to cross<br />

a road, when crossing on an EI was planned, but not possible.<br />

The models <strong>for</strong> movement and crossing on EIs and NIs are<br />

different. The following sections 4.2 and 4.3 discuss both.<br />

4.2 Sidewalk Movement<br />

With regard to computational efficiency, pedestrians are<br />

simulated with a very simple model when walking on sidewalks.<br />

Let N b a (µ,σ) = min(max(N (µ,σ),a),b) be Gaussian<br />

distributed random number with µ and σ bounded to the<br />

interval [a···b]. Each pedestrian distinguishes his base velocities<br />

<strong>for</strong> sidewalks α, <strong>for</strong> crossing with right of way β and


Figure 2. <strong>Pedestrian</strong> road crossing behavior.<br />

Figure 3. <strong>Pedestrian</strong> way: Measures and lanes.<br />

without right of way χ in � m · s −1� :<br />

α = N 1.75<br />

0.5 (1.33, 0.25) (2)<br />

β = N 1.5·α<br />

α (1.5, 0.5) (3)<br />

χ = N 2·α<br />

α (1.8, 0.5) (4)<br />

These values correspond to the literature review given in [11].<br />

Assuming that smaller interactions between pedestrians on<br />

sidewalks average in time and space, pedestrians move linearly<br />

without interaction with other pedestrians. For determining<br />

ECT , pedestrians are modeled with a base AF of<br />

AF = N +3<br />

−3 (−0.5, 1.0) (5)<br />

In order to cross a road, pedestrian p calculates ECT and enters<br />

the road, when no road user passes the current road position<br />

of p, be<strong>for</strong>e p leaves the road adding a safety distance<br />

of two seconds, as shown in Figure 2. In this example, the<br />

pedestrian will not cross the road, because the car on the right<br />

side will reach its position be<strong>for</strong>e the crossing is done with<br />

the safety distance of 2s.<br />

Crossing a road is done at right angle to the course of the<br />

EI. This is also done in linear movement, because it is unlikely<br />

that interaction with other pedestrians will occur in<br />

these situations. When a pedestrian has started crossing the<br />

road, he will not abort it. When ECT was too low (e.g., because<br />

of a negative AF), road users need to brake in order to<br />

avoid an accident. In these cases, cars are interfered by pedestrians.<br />

4.3 <strong>Pedestrian</strong> Interaction at Crossings<br />

Crossings are the places where pedestrians may interact<br />

with each other, e.g., because several pedestrians may use a<br />

traffic light at once. Thus, a microscopic model <strong>for</strong> pedestrian<br />

movement is used to model pedestrian ways, which are placed<br />

at NIs. Figure 3 shows the composition of pedestrian ways.<br />

1 function update(iteration)<br />

2 if iteration �= iterationOld then<br />

3 iterationOld ← iteration;<br />

4 checkQueue();<br />

5 <strong>for</strong>each <strong>Pedestrian</strong> p do<br />

6 determineUsableLanes())<br />

7 <strong>for</strong>each <strong>Pedestrian</strong> p do<br />

8 chooseLane()<br />

9 <strong>for</strong>each <strong>Pedestrian</strong> p do<br />

10 provideLane()<br />

11 <strong>for</strong>each <strong>Pedestrian</strong> p do<br />

12 calcV()<br />

13 <strong>for</strong>each <strong>Pedestrian</strong> p do<br />

14 f .pos ← f .pos + v;<br />

15 if f .pos ≥ l then<br />

16 f .crossingNI←false;<br />

17 remove(p);<br />

Figure 4. update()-method of way-objects.<br />

The pedestrian way is separated into w lanes (width of the<br />

crossing) and has a length of l (width of the EI to cross).<br />

The proposed model is a space continuous adaptation of the<br />

cellular automaton based model, described in [1], permitting<br />

individual pedestrian velocities, that are not covered by [1].<br />

The model reproduces the interaction between pedestrians,<br />

walking in both directions on the way object. The basic algorithm<br />

is shown in Figure 4.<br />

Whenever a pedestrian p is on a way object w, it <strong>for</strong>wards<br />

the update call to w. Lines 2 and 3 assure that the way is only<br />

updated once per iteration.<br />

Each pedestrian starting a crossing action on a way chooses<br />

its lane at first. If no free lane is available, one lane will be<br />

chosen randomly and the pedestrian will be put into a queue<br />

<strong>for</strong> waiting pedestrians. Line 4 checks <strong>for</strong> pedestrians, waiting<br />

to enter the way and adds them when their lane provides a free<br />

entry position.<br />

Each pedestrian p calculates the magnitude of usable lanes<br />

in the neighborhood N lane of its current lane as shown in<br />

equation 6.<br />

N lane = {p.lane − 1, p.lane, p.lane + 1} ∩ {1,··· ,w} (6)<br />

If possible sidestep positions of different pedestrians interfere<br />

with each other, only one of them may use the corresponding<br />

lane. Due to the avoidance of asynchronisms, the lane choosing<br />

process is divided into an update (line 8) and a provide<br />

(line 10) step.<br />

In line 8, each pedestrian p calculates the gaps g(l) to the<br />

next pedestrian <strong>for</strong> each lane l ∈ N lane in the direction of


travel of p. A rating <strong>for</strong> the lanes ϑ(l) is calculated. It is identical<br />

to g(l) and is halved if the next pedestrian is opposing<br />

traffic. ϑ(l) is limited to a maximum visual range of 10m.<br />

A usage probability of upl is assigned to each lane l ∈<br />

N lane . If the current lane p.lane of p has the maximum ϑ(l)<br />

in all lanes l ∈ N lane , its probability up p.lane will be set to<br />

95% and the residual 5% are split <strong>for</strong> the rest of lanes in<br />

N lane . When the current lane is not with maximum rating,<br />

the probabilities will be computed using equation 7.<br />

pl = ϑ(l)<br />

⎛<br />

⎞<br />

⎝ ∑<br />

l∈Nlane<br />

ϑ(l) ⎠<br />

−1<br />

∀ l ∈ N lane<br />

Each pedestrian randomly selects his new lane with the calculated<br />

probability distribution. <strong>Pedestrian</strong>s thus choose the<br />

lane, promising to be the fastest with respect to the gaps and<br />

opposing pedestrians. This also leads to the <strong>for</strong>mation of trails<br />

in both directions. In line 10, the lane changes are per<strong>for</strong>med.<br />

Each pedestrian calculates his new velocity in line 12 after<br />

equation 8.<br />

v = min(ϑ(p.lane),vmax) (8)<br />

The velocity vmax is the desired velocity of the corresponding<br />

pedestrian. Equation 8 thus leads to desired velocities<br />

bounded to the given gaps on the corresponding lanes. If no<br />

movement is possible because of opposing traffic, the two affected<br />

pedestrians will come to pass with probability ppass =<br />

0.15. The velocity then becomes vpass = 0.25 · vmax.<br />

Lines 14 to 17 per<strong>for</strong>m the movement of each pedestrian<br />

on the way and will remove it when he has reached the end of<br />

the way. The crossingNI-flag of the corresponding pedestrian<br />

is set to false and it will proceed on the other side of road or<br />

new EI in the next iteration.<br />

5 MODEL EVALUATION<br />

This section evaluates the presented model <strong>for</strong> pedestrian<br />

movement. Unless otherwise specified, experiments are done<br />

in the map extract shown in Figure 5. It is a whole city with<br />

about 89,000 inhabitants.<br />

The following subsections 5.1 to 5.3 discuss different parameters<br />

of the pedestrian model.<br />

5.1 <strong>Pedestrian</strong> Velocity<br />

This subsection discusses pedestrian velocities during simulation.<br />

Each pedestrian is enhanced by an analysis module<br />

which protocols velocities and other parameters. The velocities<br />

are separated <strong>for</strong> different incidents. The average velocity<br />

v over the whole walk of each pedestrian is recorded. The<br />

velocities on sidewalks vs, during road crossing with vr and<br />

without vr right of way are recorded as well.<br />

The simulation experiment is done with a warm-up phase<br />

of 2,500 iterations, followed by a measurement phase of<br />

(7)<br />

Figure 6. Distribution of walked velocities.<br />

quantity<br />

quantity<br />

Figure 7. Distribution of aggressiveness.<br />

100,000 iterations. The composition of road users is 50%<br />

cars, 15% bicycles and 25% pedestrians. The amount of traffic<br />

participants is 3,000 which is kept constantly during the<br />

simulation time. Whenever a traffic participant finishes its<br />

travel, a new one will be generated.<br />

As shown in figure 6, the basic effects discussed in section<br />

3 are reproduced by the simulation model (vs < vr < vr). The<br />

measured velocities correspond well to field studies (e.g., [6,<br />

9, 14]).<br />

5.2 <strong>Pedestrian</strong> Aggressiveness<br />

The distribution of aggressiveness of all pedestrians is<br />

recorded <strong>for</strong> the whole simulation. Figure 7 shows a histogram<br />

of the measured data with its probability density function<br />

f and a boxplot.<br />

The shown distribution fits the claimed characteristics in<br />

section 3 and [2, 5]. Figure 8 illustrates the process of becoming<br />

aggressive. In this example, a pedestrian initially has


1224m MAINS<br />

²<br />

Multimodal<br />

Innercity<br />

<strong>Simulation</strong><br />

IM<br />

Multimodale Innerstädtische Straßenverkehrssimulation<br />

Figure 5. Map extract of the city Hanau, Germany with an accumulated length of roads of 548km, amount of EIs: 5,400 and<br />

amount of NIs: 3,878.<br />

Figure 8. Change of aggressiveness over time.<br />

a basic AF of about +0.4, leading to a behavior which is overcautious.<br />

From point a to c, the pedestrian has to wait <strong>for</strong> a<br />

sufficient gap in order to cross a road. His aggressiveness increases<br />

with step size 0.1 · s −1 . This value is not documented<br />

in literature but shows the basic principle. Finally, the crossing<br />

action takes place and the aggressiveness recovers.<br />

5.3 <strong>Pedestrian</strong> Crossings<br />

<strong>Pedestrian</strong> crossings can be analyzed with help of the well<br />

known density (ρ) - mean velocity (v) diagram. The traffic<br />

density of a pedestrian way is calculated as stated in equation<br />

9.<br />

ρ = #pedestrians<br />

C<br />

(9)<br />

The capacity of a pedestrian way is C = w·l ·(0.457) −1 . This<br />

definition is according to [1] which defines cells with width<br />

of 0.457m being fully occupied by one pedestrian.<br />

The ρ - v relation has to be divided according to the amount<br />

of pedestrians walking in both directions, because different<br />

compositions lead to different ρ - v relations.<br />

In order to analyze the relation, a single pedestrian way<br />

object is used <strong>for</strong> simulation. It has five lanes and a length of<br />

l = 10 · 0.457m and thus leads to a realistic pedestrian crossing.<br />

The amount of pedestrians is set to one <strong>for</strong> the first run<br />

and is then increased by 1, until 75 runs have been made.<br />

The results represent average values of 10 replications <strong>for</strong><br />

each setting. After a settlement phase of 500 iterations, 5,000<br />

iterations are used <strong>for</strong> measurements of the average velocity<br />

v of all pedestrians on the way. This procedure is per<strong>for</strong>med<br />

<strong>for</strong> different compositions of directions of travel with<br />

50%,60%,··· ,100% pedestrians walking into one direction<br />

and the rest into the other direction. Figure 9 shows the resulting<br />

diagram.<br />

As can be seen, the maximum density differs in relation to<br />

the composition of walking directions. This results from the<br />

queuing process of the algorithm, shown in figure 4. <strong>Pedestrian</strong>s<br />

walk faster, when there is no opposing traffic and there<strong>for</strong>e<br />

the distances between two subsequent pedestrians increase.<br />

Figure 9 shows that the more balanced the distribution of<br />

walking directions is, the higher the maximum values of ρ<br />

get and the lower the mean velocity v. This is in line with the<br />

results presented in [1] with the difference that only realistic<br />

densities <strong>for</strong> urban traffic road crossings are generated.<br />

It seems to be likely that only parts of the shown figure 9<br />

occur in urban traffic. Hence, another experiment comes back


100<br />

90<br />

80 7060<br />

50<br />

Figure 9. Density velocity relation <strong>for</strong> a pedestrian way.<br />

Figure 10. Density velocity relation <strong>for</strong> all pedestrian ways<br />

in Hanau with relative frequencies fi (ρ).<br />

to the scenario of the city Hanau, shown in figure 5. Every<br />

pedestrian way in the simulation records pairs of data <strong>for</strong> ρ<br />

and v, whenever at least one pedestrian uses it. The measured<br />

values of ρ are grouped into ρ-intervals of width 0.005. This<br />

is done because the huge amount of metered values would<br />

lead to point clouds not enabling to see the underlying effects.<br />

Intervals with less than 11 values are dropped, because<br />

of the risk of overvaluing outliers. The composition of walking<br />

directions is not distinguished <strong>for</strong> this experiment. Figure<br />

10 presents the ρ - v plot <strong>for</strong> the urban simulation.<br />

Additionally, the maximum velocity vmax <strong>for</strong> each group<br />

of ρ and the relative frequencies fi (ρ) are plotted. The curves<br />

300 350 400 450 500<br />

averaged travel time (cars)<br />

0 1.000 2.000 3.000 4.000<br />

#pedestrians<br />

Figure 11. Influence of pedestrians on urban car traffic:<br />

Comparison of travel times of cars with varying amounts of<br />

pedestrians. Each boxplot represents 1,000 values.<br />

<strong>for</strong> v and vmax result from regression analysis. The plot<br />

shows that most results have been generated at low densities.<br />

The values of vmax decrease rapidly with increasing ρ,<br />

because fast pedestrians are hindered by slower ones. A maximum<br />

density of ρmax = 0.16 though suggests that pedestrians<br />

could have an influence on urban road traffic, because of<br />

roads being blocked by pedestrians notably times.<br />

6 INFLUENCE ON URBAN TRAFFIC<br />

The previous section has shown that the developed model<br />

<strong>for</strong> pedestrian movement reproduces the basic effects and coherences<br />

as reported previously in literature. This section investigates<br />

the influence of simulated pedestrians on urban<br />

traffic. Simulating pedestrians leads to additional computational<br />

ef<strong>for</strong>t and there<strong>for</strong>e should only be done if a significant<br />

effect on urban traffic can be shown (or if pedestrians are in<br />

focus of the corresponding study).<br />

The map excerpt presented in figure 5 is used <strong>for</strong> another<br />

experiment. 2,000 simulated road users (95% cars, 5% bicycles)<br />

are created. After a settlement phase of 1,000 iterations,<br />

the travel times of each car leaving the simulation are<br />

recorded. This is done <strong>for</strong> 10,000 iterations and afterwards<br />

averaged to the value t. The amount of road users is kept<br />

constantly through the simulation by adding a new road user,<br />

whenever another one has left the simulation.<br />

The experiment is repeated with identical road users complemented<br />

with 0, 1,000, 2,000, 3,000 and 4,000 pedestrians.<br />

The whole procedure is repeated 1,000 times <strong>for</strong> all five settings.<br />

Figure 11 shows the simulation results.<br />

A tendency to increasing travel times of cars <strong>for</strong> increasing<br />

amounts of pedestrians can be observed. The jitter of the<br />

simulation results also increases, due to the probabilistic sim-


#pedestrians t [s]<br />

0 410.9319<br />

1,000 416.3292<br />

2,000 419.8662<br />

3,000 423.2393<br />

4,000 426.7230<br />

Table 1. Comparison of average travel times of cars t [s]<br />

with different amounts of pedestrians. Averaged over 1,000<br />

simulation runs each.<br />

Hypothesis p p < α *<br />

H a 0 3,157 · 10 −8 �<br />

H b 0 1,478 · 10 −4 �<br />

H c 0 5,37 · 10 −4 �<br />

H d 0 2,803 · 10 −4 �<br />

Table 2. p-value comparisons <strong>for</strong> H a 0 ···Hd 0 .<br />

ulation model. Table 1 compares the average travel times, extracted<br />

from the simulation results.<br />

The results show an increasing travel time <strong>for</strong> cars with increasing<br />

amounts of pedestrians. Let tt (x) be the averaged<br />

travel time obtained with x · 10 3 pedestrians. In order to examine<br />

if an increasing amount of pedestrians results in increasing<br />

travel times <strong>for</strong> cars in the simulation, the hypotheses<br />

shown in equations 10 to 13 are proposed.<br />

H a 0 : tt (0) ≥ tt (1) (10)<br />

H b 0 : tt (1) ≥ tt (2) (11)<br />

H c 0 : tt (2) ≥ tt (3) (12)<br />

H d 0 : tt (3) ≥ tt (4) (13)<br />

The free statistics software R-project 3 is used to run t-tests<br />

in order to find out if significant differences are given in the<br />

measured data. This is done via multiple testing. Each hypothesis<br />

includes at least one simulation result control sample<br />

which is used twice <strong>for</strong> testing. The error level α = 0.05 thus<br />

has to be adjusted after the method of Bonferroni to:<br />

α * = α<br />

= 0.025 (14)<br />

2<br />

The results of the t-tests are shown in table 2. All results<br />

of the statistical tests are significant <strong>for</strong> the selected error<br />

level and there<strong>for</strong>e indicate that a lower number of pedestrians<br />

leads to lower travel times on average:<br />

tt (0) < tt (1) < tt (2) < tt (3) < tt (4) (15)<br />

The results indicate that pedestrians do actually have an influence<br />

on car traffic: <strong>Pedestrian</strong>s slow down car traffic in urban<br />

scenarios in the built simulation system MAINS 2 IM.<br />

3 http://www.r-project.org/<br />

7 SUMMARY AND PERSPECTIVES<br />

The behavior of pedestrians in urban traffic has been discussed.<br />

A bi-modular model <strong>for</strong> pedestrian movement has<br />

been developed, taking account of interaction on pedestrian<br />

crossings. It could be shown that the model can replicate observations<br />

with respect to field studies. The correlation of traffic<br />

density and mean velocity on pedestrian crossings could<br />

be reproduced. The presented model <strong>for</strong> pedestrian movement<br />

deals with individual velocities based on field studies.<br />

The traffic of whole cities can still be simulated under usage<br />

of the presented model.<br />

<strong>Simulation</strong> results indicate that pedestrians slow down road<br />

traffic in a significant range. In future work it should be examined<br />

if an analysis of simulation results leads to an understanding,<br />

how often and how intense these influences take<br />

place in relation to different areas of a simulated city. After<br />

this step, only the effects (cars need to brake, because of<br />

pedestrians using traffic lights, pedestrian crossings or crossing<br />

roads without right of way), but not the originators (the<br />

pedestrians) would be needed to be simulated.<br />

So far, only the influences of pedestrian behavior on cars<br />

has been evaluated. It would be interesting to see how different<br />

intervention actions on urban traffic, e.g., different velocity<br />

restrictions or new traffic-free environments affect pedestrian<br />

travels.<br />

The simulation system is able to readout bus routes from<br />

OpenStreetMap. When a bus stops in real world, several<br />

pedestrians enter and leave the bus and thus strong effects in<br />

road traffic could emerge, especially <strong>for</strong> high traffic densities.<br />

Currently buses are implemented, but pedestrians do net yet<br />

enter or leave them.<br />

<strong>Traffic</strong> engineers only have two main possibilities to enable<br />

pedestrians to cross roads: (a) traffic lights and (b) pedestrian<br />

crossings. These are only two actions. An optimization<br />

method, e.g., Simulated Annealing could be used to minimize<br />

travel times <strong>for</strong> road users under optimization of interchanging<br />

(a) and (b) at the places, one of them is set. This could<br />

also be done in the face of minimization of fuel consumption<br />

and CO2 emissions <strong>for</strong> whole cities.<br />

REFERENCES<br />

[1] Victor J. Blue and Jeffrey L. Adler. Cellular automata<br />

microsimulation <strong>for</strong> modeling bi-directional pedestrian<br />

walkways. Transportation Research Part B: Methodological,<br />

35(3):293 – 312, 2001.<br />

[2] Marcus A. Brewer, Kay Fitzpatrick, Jeffrey A.<br />

Whitacre, and Dominique Lord. Exploration of pedestrian<br />

gap-acceptance behavior at selected locations.<br />

Transportation Research Record: Journal of the Transportation<br />

Research Board, 1982:132–140, 2006. ISSN:<br />

0361-1981.


[3] Jörg Dallmeyer, Andreas D. Lattner, and Ingo J. Timm.<br />

From GIS to Mixed <strong>Traffic</strong> <strong>Simulation</strong> in <strong>Urban</strong> <strong>Scenarios</strong>.<br />

In Jason Liu, Francesco Quaglia, Stephan Eidenbenz,<br />

and Stephen Gilmore, editors, 4th International<br />

ICST Conference on <strong>Simulation</strong> Tools and Techniques,<br />

SIMUTools ’11, Barcelona, Spain, March 22 - 24, 2011,<br />

pages 134–143. ICST (Institute <strong>for</strong> Computer Sciences,<br />

Social-In<strong>for</strong>matics and Telecommunications Engineering),<br />

Brüssel, 2011. ISBN 978-1-936968-00-8.<br />

[4] Jörg Dallmeyer, Andreas D. Lattner, and Ingo J. Timm.<br />

Data Mining <strong>for</strong> Geoin<strong>for</strong>matics: Methods and Applications,<br />

chapter GIS-based <strong>Traffic</strong> <strong>Simulation</strong> using OSM.<br />

Cervone, Guido and Lin, Jessica and Waters, Nigel<br />

(eds.) Springer, 2012. (accepted).<br />

[5] Sanghamitra Das, Charles F. Manski, and Mark D.<br />

Manuszak. Walk or wait? an empirical analysis of street<br />

crossing decisions. Journal of Applied Econometrics,<br />

20(4):529–548, 2005.<br />

[6] K. Fitzpatrick, M. A. Brewer, and S. Turner. Another<br />

look at pedestrian walking speed. In Proceedings of<br />

the 85th Annual Meeting of the Transportation Research<br />

Board, Washington, DC, USA., 2006.<br />

[7] Dirk Helbing and Péter Molnár. Social <strong>for</strong>ce model <strong>for</strong><br />

pedestrian dynamics. Physical Review E, 51(5):4282–<br />

4286, May 1995.<br />

[8] Roger L. Hughes. The flow of human crowds. Annual<br />

Review of Fluid Mechanics, 35(1):169–182, 2003.<br />

[9] Muhammad Moazzam Ishaque. Policies <strong>for</strong> <strong>Pedestrian</strong><br />

Access: Multi-Modal Trade-off analysis using Micro-<br />

<strong>Simulation</strong> Techniques. PhD thesis, Centre <strong>for</strong> Transport<br />

Studies Imperial College London, 2006.<br />

[10] Muhammad Moazzam Ishaque and Robert B Noland.<br />

<strong>Pedestrian</strong> modeling in urban road networks: Issues,<br />

limitations and opportunities offered by microsimulation.<br />

9th Annual Computers in <strong>Urban</strong> Planning<br />

and <strong>Urban</strong> Management, London, page 9, 2005.<br />

[11] Muhammad Moazzam Ishaque and Robert B. Noland.<br />

Behavioural issues in pedestrian speed choice and street<br />

crossing behaviour: A review. In Transport Reviews: A<br />

Transnational Transdisciplinary Journal, volume 28(1),<br />

pages 61–85, Jan 2008.<br />

[12] Andreas D. Lattner, Jörg Dallmeyer, and Ingo J. Timm.<br />

Learning dynamic adaptation strategies in agent-based<br />

traffic simulation experiments. In Ninth German Conference<br />

on Multi-Agent System Technologies (MATES<br />

2011), pages 77–88. Springer: Berlin, LNCS 6973,<br />

Klügl, F.; Ossowski, S., 2011. ISBN: 978-3-642-24602-<br />

9.<br />

[13] Michele Ottomanelli, Leonardo Caggiani, Iannucci<br />

Giuseppe, and Domenico Sassanelli. An adaptive<br />

neuro-fuzzy inference system <strong>for</strong> simulation of pedestrians<br />

behaviour at unsignalized roadway crossings. 14th<br />

Online World Conference on Soft Computing in Industrial<br />

Application, 14, 2009.<br />

[14] Y. Tanaboriboon, S. S. Hwa, and C. H. Chor. <strong>Pedestrian</strong><br />

characteristics study in singapore. Journal of Transportation<br />

Engineering, 112:229–235, 1986.<br />

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BIOGRAPHY<br />

Jörg Dallmeyer received the bachelor degree (2008) as<br />

well as the master degree (2009) in computer science at the<br />

Goethe University of Frankfurt am Main, Germany. Since<br />

December 2009, he is a PhD student at the chair <strong>for</strong> “In<strong>for</strong>mation<br />

Systems and <strong>Simulation</strong>” at the Goethe University<br />

Frankfurt. His research interests are actor based simulation<br />

<strong>for</strong> the field of traffic simulation under consideration of multimodal<br />

traffic and the building of simulation systems from<br />

geographical in<strong>for</strong>mation.<br />

Andreas D. Lattner received the Diploma degree in computer<br />

science at the University of Bremen, Germany in 2000.<br />

From December 2000 to March 2007 he was working as research<br />

scientist at the Center <strong>for</strong> Computing Technologies<br />

(TZI) at the University of Bremen. In 2007 he obtained the<br />

doctor’s degree <strong>for</strong> his thesis on “Temporal Pattern Mining<br />

in Dynamic Environments”. He works now as a postdoctoral<br />

researcher at the chair <strong>for</strong> “In<strong>for</strong>mation Systems and <strong>Simulation</strong>”<br />

at the Goethe University Frankfurt. His research interests<br />

include knowledge discovery in simulation experiments,<br />

temporal pattern mining, and multi-agent systems.<br />

Ingo J. Timm received Diploma degree (1997), PhD<br />

(2004) and venia legendi (2006) in computer science from<br />

University of Bremen. From 1998 to 2006, he has been PhD<br />

student, research assistant, visiting and senior researcher, and<br />

managing director at University of Bremen, Technical University<br />

Ilmenau, and Indiana University Purdue University<br />

- Indianapolis. In 2006, Ingo Timm was appointed full professor<br />

<strong>for</strong> In<strong>for</strong>mation Systems and <strong>Simulation</strong> at Goethe-<br />

University Frankfurt. Since 2010, he holds a chair <strong>for</strong> Business<br />

In<strong>for</strong>matics at University of Trier. He works on in<strong>for</strong>mation<br />

systems, knowledge-based systems in logistics and<br />

medicine. His special interests lie on strategic management<br />

of autonomous software systems, actor-based simulation and<br />

knowledge-based support to simulation systems.<br />

Acknowledgement This work was made possible by<br />

the MainCampus scholarship of the Stiftung Polytechnische<br />

Gesellschaft Frankfurt am Main.

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