hello guys im stuck for quite a while with this problem and i badly need ur help.
in fact i wanna make the red rectangle slow down when it comes close to the blue one. it would be nice if they both move at the same speed. ive tried several different techniques but has failed so far.
any help plz...

import Tkinter as tk
import time
import sys
import datetime as dt 
from Tkinter import *



root=tk.Tk()
root.title("Traffic Simulation")
canvas = tk.Canvas(root, width=1000, height=400, bg="#FFFFFF")

canvas.pack()

# create car

car1=canvas.create_rectangle(10,170,30,180, outline='blue', fill='blue')
car2=canvas.create_rectangle(-30,170,-10,180, outline='red', fill='red')

def minus(self, a,b='unary'):
    if b=='unary':
        return map(lambda x:-x,a)
    else:
        return map(lambda x,y:x-y,a,b)


# move car
while True:
    time.sleep(0.025)
    canvas.move(car1, 2, 0)
    canvas.move(car2, x, 0)
    a=canvas.coords(car1)
    b=canvas.coords(car2)
    print minus(a,b)
    if (minus(a,b)) ==['0.0', '-170.0', '-20.0', '-180.0']:
        x=1
    canvas.update()

root.mainloop()

You are importing Tkinter twice, first with a namespace and then without, kind of goofy. This "Traffic Simulation" must be homework, because I have seen this import approach a fair number of times on several forums.

some advice would be appreciated... thanks