4 way traffic light with countdown timer

hi. can anybody help me in constructing a 4-way traffic light with countdown timer. even only using a single digit, (9,8,7,6,5....0)
please help. thanks in advance. i have search 4 way traffic light circuits. but it only uses 555 timer, with no countdown timer. thanks..
Incorporating the countdown 7 segment display would be very easy. All you would need is a count down seven segment display driver, and a seven segment display. Maybe a CD40110 Up/Down counter chip would work, the cost is about $1-$2 on eBay. Any seven segment disply would work, I sell 10mm Yellow ones and would send you one for free if you wanted to try it, you would just need to send me self addressed stamped envelope or $1 into paypal for shipping/materials. I dont have any Down counters, sorry.