What percent of the railroad tie market in the United States uses wood ties?
Wood maintains a 93%+ share of the market for ties installed in North America. Wood not only has certain desirable performance properties that make it ideal for a wide variety of track applications, but also the initial and long-term life cycle economics of the wood tie are one of the most important reasons that wood is so overwhelmingly chosen. The paper entitled Comparative Crosstie Unit Value and Costs gives more details on the economics of wood as compared to alternative materials.
