Modeling an Intersection with Rules for Traffic Flow in MATLAB

In summary, the individual is trying to model an intersection using different rules and is having difficulty getting it to work. They have created a grid with different rules for cars to move and stop at the intersection, but are struggling with implementing these rules. They have tried using the "&" symbol in MATLAB for the first time and believe this may be causing issues. They are now trying a different approach but are still struggling to make it work. They are asking for suggestions and have provided code for their attempts at the second part of the intersection model.
  • #1
gryphon1221
9
0
Hi, I am trying to model an intersection using different rules but I am having a hard time getting the thing to work in the simplest stage. I know there is probably an easier way to do this but I am trying to do it this way:

clear
grid=zeros(10,10); %grid creation
grid2=zeros(10,10);
grid3=zeros(10,10);
grid(1:4,1:4)=2; %empte spaces representing city blocks
grid(7:10,1:4)=2;
grid(1:4,7:10)=2;
grid(7:10,7:10)=2;

grid(6,2)=1; %initial grid coords for cars
grid(6,4)=1;
grid(7,6)=1;
grid(5,7)=1;
grid(5,9)=1;
grid(4,5)=1;
grid(2,5)=1;
grid(9,6)=1;



tfinal=100;
for t=1:10
random=randi(10,1);
if grid(6,10)==1;
grid2(6,10)=0;
end
if grid(6,9)==1;
grid2(6,10)=1 & grid3(6,9)==-1;
end
if grid(6,8)==1;
grid2(6,9)=1 & grid3(6,8)==-1;
end
if grid(6,7)==1;
grid2(6,8)=1 & grid3(6,7)==-1;
end
if grid(6,6)==1;
grid2(6,7)=1 & grid3(6,6)==-1;
end
if grid(6,5)==1;
grid2(6,6)=1 & grid3(6,5)==-1;
end
if (grid(6,4)==1) && 0<t<=(tfinal/10)
grid2(6,5)=1 & grid3(6,4)==-1;
end
if grid(6,3)==1;
grid2(6,4)=1 & grid3(6,3)==-1;
end
if grid(6,2)==1;
grid2(6,3)=1 & grid3(6,2)==-1;
end
if grid(6,1)==1;
grid2(6,2)=1 & grid3(6,1)==-1;
elseif grid(6,1)==0 & random>=5;
grid2(6,1)=1;
end
grid2=grid3+grid2;
grid=grid2;
end

This is just the first of 4 aspects of the intersection node. I want the cars to move ahead in each column, except a time limitation on column 5 representing the signal. This is my first time using & for anything in matlab, and I have a feeling not understanding its use is causing me problems. I have been trying for a while and I am just plain stuck now. Anyone have any suggestions?
 
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  • #2
I am taking a different approach but still can't get it to work.

For the initial movement I got it, but after a time delay I can't seem to figure it out. I want the vector to move when 12<t<=22, but when I type the inequality into a conditional it seems to not be working. Here is the code I am using for the second movement right now (not working)

for t=1:22
if ((tfinal/10)+1)<t<=((2*tfinal/10)+2)
left_traffic_post_inter=left_traffic(1:6);
elseif t>((2*tfinal/10)+2)
left_traffic_post_inter=circshift(left_traffic_post_inter,[0 -1]);
end

if left_traffic_post_inter(1)==1
left_traffic_post_inter(1)=0;
end
left_traffic=[left_traffic_post_inter(1:6) left_traffic(7:10)];
end

The second part of the code is when the intersection switches again and the cars stop moving before the intersection, but finish moving if they are in or after the intersection. Thanks for any insight.
 

1. What is the purpose of modeling an intersection with rules for traffic flow in MATLAB?

The purpose of modeling an intersection with rules for traffic flow in MATLAB is to simulate and analyze the behavior of traffic at a specific intersection. This can help transportation engineers and planners make informed decisions about traffic control measures, such as signal timings and lane configurations, in order to improve traffic flow and safety.

2. What are the key components of a traffic flow model in MATLAB?

The key components of a traffic flow model in MATLAB include the road network, traffic demand (i.e. number of vehicles), vehicle characteristics (e.g. speed, acceleration), and traffic control devices (e.g. traffic signals, stop signs). These components are used to create a simulation of how vehicles move through the intersection under different conditions.

3. How does MATLAB handle the modeling of complex traffic behaviors, such as car-following and lane changing?

MATLAB has various built-in functions and tools that can be used to model complex traffic behaviors. For example, the Simulink blockset includes the Vehicle Dynamics Blockset which allows for the simulation of car-following and lane changing. Additionally, custom algorithms and rules can be programmed using MATLAB's scripting language to accurately model these behaviors.

4. Can we use the traffic flow model in MATLAB to predict real-world traffic behavior?

Yes, the traffic flow model in MATLAB can be calibrated and validated using real-world traffic data to accurately predict traffic behavior at a specific intersection. This can help engineers and planners make more informed decisions about traffic control measures and their potential impacts on traffic flow.

5. Can the traffic flow model in MATLAB be used to optimize traffic signal timings?

Yes, the traffic flow model in MATLAB can be used to optimize traffic signal timings by simulating different signal timing plans and evaluating their effectiveness in improving traffic flow and reducing delays. This can help engineers and planners make data-driven decisions about signal timing adjustments to improve overall traffic efficiency at an intersection.

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