You are asked to develop a ladder logic diagram for the traffic light of a relatively busy $4-$way intersection.

Based on this, you are asked to model the behavior of one intersection $($Fair Road and Veterans Highway$).$

You will need to collect data on light cycle times, and I must emphasize that this should be done in a safe

manner. I am providing some assumptions, but you will need to make a few others. Please make sure you $\_()$

state them clearly. Assumptions:

Assume that the intersection is symmetrical $($as shown in the drawing$)$ and that the behavior from

all directions is the same.

The traffic light operates on two modes: day mode $($from $6$ am until $11$ pm $)$ and night mode $(11$ pm

until $6$ am $).$

There is a left turn light in each direction.

There are weight plate sensors in each lane at the intersection $($shown in the blue squares in the

schematic$).$ These detect the presence of the first vehicle in each lane. Label these variables

depending on whether they are used for signaling cars wanting to turn left $($WL$1,$ WL$2,$ WL$3,$ WL$4)$ or

go straight $($WS$1,$ WS$2,$ WS$3,$ WS$4).$

At each intersection, there are two push buttons $($CrossPB$)$ two visual "walk" displays $.$ A$...($Walk$),$

and two speakers $($SpeakWalk$).$ The visual and auditory signals are used to inform pedestrians who

have pushed the button when it is safe to cross. These outputs only occur in the immediate cycle

after the button is pushed. If no button is pushed, there is no signal. This pedestrian capability is

provided both during day or night operation. It does not affect any traffic light duration in any

direction, only informs pedestrians about when it is safe to cross.

Day mode operation:

You will need to go to the intersection $($during a busy time on a weekday$)$ to observe and understand

the behavior of the light. For example, the cycling and sequence of the lights, the duration of each

light $($left turn, green, red, yellow$),$ etc. Once again, please do this data collection from a safe distance.

Assume the cycles are constant. For example: the duration of the green light is always the same and

is not reduced because of the presence of cars elsewhere.

The left turn signal only operates whenever there is a car wanting to turn left $($as detected by the

weight plate sensor$).$ For this to happen, the car needs to activate weight plate sensor before the

green light comes up $($that is$,$ while on red$).$

Night mode operation:

You do not need to collect time or information for this mode. We will assume the behavior.

During nighttime $($that is after $11$ pm $),$ let's assume that the traffic light switches to a mode that

provides a permanent green light to those traveling in either direction along the busier Fair Road and

a permanent red light to those traveling along Veterans Highway.

Once a vehicle traveling along Veterans arrives to either lane the intersection, the sensors detect this

presence and the light immediately turns to yellow $($along the Fair Road direction$)$ and after the

appropriate yellow time $($same as found during daytime data collection$),$ the lights turn to red $($Fair

Road$)$ and green $($both left turn and straight in Veterans$)$ respectively. Program code layout

Please try to model the set of inputs and outputs for each street in a separate section in LogixPro.

Label these as Veterans North, Veterans South, etc. Also if you have external clocks, timers or

counters that apply to all intersections create an additional section that contains these. Called this

section "Global". You will then have a total of five $(5)$ sections. Ask me before deviating from this and

creating a more complicated layout.

Traffic Light naming convention: Color $+$ direction of green $($if needed$)+$ Direction of Travel

Examples:

RedVeteransE

GreenLeftFairS

GreenStraightVeteransW

Solve using LogixPro.