Traffic Jam is a simple web service for demonstrating slow networks. It can be used for simulating slow network traffic for testing or teaching purposes.
Traffic Jam is hosted on Heroku http://trafficjamapp.herokuapp.com
Traffic Jam expects a query string of delay to indicate how long it should delay the response. This should be a number representing the milliseconds for the delay. Because Heroku throttles requests that take longer than 30 seconds the maximum delay is 28000.
curl -i "http://trafficjamapp.herokuapp.com/?delay=5000"
After the delay you'll get a response
HTTP/1.1 200 OK Content-Type: text/plain Content-Length: 43 Connection: keep-alive Response from Traffic Jam with 5000ms delay
Note the response time isn't going to be exactly 5000 milliseconds but Traffic Jam will respond after that amount of time. Networks, DNS lookups etc may make the response time longer.
That's all it does. I told you it was simple.