The Logic of speed a simple comparison

		By Car	Bike	Elevated Bike
	Average wait at lights( seconds)
	Distance Traveled(miles)
	Number of lights in whole trip
	Top speed( Miles/Per hour)
	Time to reach top speed(secs)
	Time to reach stop(secs)
	time moving ( seconds)
	Time stopped (seconds)			0
	Time to stop/start(seconds)
	distance accelerating(miles)
	Average inter light spaceing(miles)
	Total journey time (mins)
	Average speed (MPH)

Notes: The average wait at lights is how long you spend on average waiting at the traffic lights. This can include zero for when you go though a green light ! The average can be very journey dependent - why not try counting up your trip to work one morning ? Why not count the number of lights too, and while you are at it many cars let you set a second pedometer so you can find the distance to work. Your average speed might surprise you !

For some trips with lots of lights close together the distance spent accelerating and decelerating is greater than the distance to work. In reality you would never reach your full speed. This calculator cannot yet handle this and gives false readings for the 'distance accelerating'. You can fix this by reducing your maximum speed.

What can be noticed is that if you use a freeway for a long journey then you are likely to find the distance is growing and the number of lights does not. Hence the average speed increases. Strangely this is exactly what the elevated way cycle is trying to do for bikes ( and incidentally that PRT is trying to do for trains). You might find that the freeway you are running on is elevated too ( I wonder why :-))

feel free to play but for many journeys under 5 miles the Bike on street is slower than the car, but the car is slower than the elevated cycle route.

Naturally there are some things I have not included in this . For example I don't include any distance/stops which might be spent getting to the skyway system. I also assume the bike does not have to go up hill ( and go slower) and the car does not slow going round corners. This calculator is really to illustrate the point with out getting too bogged down in details

Experiments you might like to try.

• Try making the bike distance longer than the car simulate choosing safe back streets and cycle lanes.
• Try making the car distance longer to simulate using one way streets over direct streets.
• Try reducing the car speed to 25 or 20 miles per hour to simulate car congestion.
• Try adding more time at the lights while you try to find a parking space.
• Try reducing the stop distances to see the effect of buying the most powerful sports car you can find on your journey to work.
• Try increasing the elevated bike speed to 17mph to simulate the use of wind and travelators (or just pedaling faster) to increase overall speed.

What you should notice is that for all journeys under 5 miles the elevated cycle lane will be quicker. This 5 mile 20 minute trip is just the kind of short trip where cars engines are still warming up and at there most polluting. Oddly enough 48% of all commute journeys in the US are under 5 miles. Done 3-5 times a week in both directions this would give just the amount of regular exercise doctors recommend. Back to the main argument.