Bike or Walk Short Trips, Save Money, Improve Health

Biking to work, are you absurd? That’s twenty miles. Plus I have to take my children to school. What about the store down the street? Only a mile away, that is more achievable – that can have a huge impact.

The small errands for forgotten ingredients for dinner can tally up – wasting gas, expanding your carbon footprint, and incurring needless spending on the ever rising price of gas. If the place you are going is within a few miles why not get exercise, get outside, and save money. Why not ride a bike or walk? That small choice can make you, your wallet, and the environment feel a lot better.

The Device

The wheel. An invention that changed the way humans move objects and themselves across various terrain. Take this and combine it with the mechanical advantage of gears and the bike is one of the most efficient devices for travel.  The foot. Seriously, the human foot is one of the most efficient biomechanical transportation devices to come out of evolution. Our springy arch is built to carry us great distances and protect our joints. While two legs may be slower than four, we can go farther and longer with our increased efficiency over quadrupeds.

The efficiency of either mode of transportation – biking or walking – when compared to that of a car is impressive and impossible to ignore.  First the bike. The bike, compared to a car, comes out 10 times more efficient in terms of energy used to maintain motion alone. This number comes out of how much of the energy put into the bike goes into motion compared to the amount of energy a car needs to travel the same distance.

In an internal combustion engine pistons move up and down due to small explosions of gasoline in each cylinder. This motion is transferred to the crankshaft, that turns the axle, that spins the wheels. In this internal combustion system the average car wastes 80% of the energy in the form of sound and heat, which is why your engine must be cooled constantly while running. That leaves only 20% of energy put into the motion of the vehicle.

Turning to the bicycle, of the energy put into the pedals 95% to 99% of the energy is converted into motion depending on the quality of the bike. The energy lost due to heat is minimal compared to that of a car. In fact, heat generation is the cause of much of the inefficiency in machines.

Now on foot. Given terrain, weight, age, and weather, it takes anywhere from 30 to 100 Calories to walk a mile. Let’s crudely translate this into the unit of measure that we use on cars, Miles Per Gallon (MPG). First, there are roughly 31,000 Calories in a gallon of gas. If we simply divide this by a conservative 100 Calories per mile we see that we humans get about 310 MPG. Better than any gas powered car ever built and some 10 times better than the average car on the road today.

The efficiency of a car is almost disgusting when compared to that of our bodies on foot or on a bike.

Residential

To give cars a fighting chance let’s use a Honda Accord with 24 MPG during city driving for our calculations. Assume gas is $3.50 a gallon. In our Honda that’s $0.15 per mile. Let’s look at just the trips in the car that we want to eliminate with biking or walking. Say you take 6 two-mile trips each week. That costs $1.80 a week in gas or $94 a year. There is a hidden cost of 520 lbs of CO2 each year for these short trips alone. The use of a less efficient car only increases these savings. Choosing to bike or walk these short errands can save you money and shrink your carbon footprint at the same time.

Of the 300-million-plus population in America, if only one million adopted this practice the CO2 savings would be equivalent to taking nearly 43,000 cars off the road each year.

There are also hidden savings to switching to biking or walking and becoming that much healthier in the amount of money that would be saved on health care expenses.

Business

Bike messengers have been used for over a hundred years. Records show the use of bike messengers by the Paris Stock Exchange in the 1870s. Businesses in Manhattan and London have long used bike couriers for all kinds of deliveries. Still ubiquitous in NYC is the use of bike messengers to deliver food.

by Cedric Cogell and Joshua Cogell

Cedric Cogell and Joshua Cogell – two brothers who discuss everything from quantum physics to the best way to reduce their mile-splits have come together to write about environmentalism. Joshua is a junior at Creighton University studying Chemistry. Cedric is a senior at Columbia University studying abstract Mathematics and Mechanical Engineering.