A Morgan Stanley research note provided to Business Insider discusses how falling oil prices could affect different industries. One of the industries they examined was freight shipping.

The note includes this fascinating chart comparing speed, price, and volume for various types of freight transportation.

Air express and ground parcel services are extremely quick but also very expensive. Meanwhile, individual shipments on these modes tend to be comparatively small: A freight airplane can carry just a few tons of cargo, while a giant barge can carry nearly 20,000 20-foot-long containers.

Full truckloads and less-than-full truckloads (LTL) are slower but vastly cheaper and with a higher capacity than the two faster freight options. Trains and ships are very cheap with very high capacities but are very slow.

Falling oil prices, and thus transportation fuel costs, will have different effects on these different modes, according to Morgan Stanley. They observed that freight carriers generally charge customers fuel surcharges based on lagged recent prices. Carriers like trucking companies tend to have short lags, basing these surcharges on diesel prices from the past week or so, while rail and parcel carriers have longer lags.

Morgan Stanley concludes that falling fuel prices can, in the short term, provide a windfall to those carriers with longer lags, although a prolonged drop in prices would eventually cut into these profits.

Morgan Stanley also noted that falling oil prices could indirectly benefit the higher-cost, faster modes of transportation, like air express and ground parcel. A big part of why these modes are so expensive is their higher rate of fuel use, so a prolonged drop in fuel prices could reduce the difference in costs between these and slower, cheaper, less fuel-intensive carriers like trucks, trains, and ships. This could lead to greater demand for the faster options, especially because they are more consumer-focused than the production-heavy trains and barges.