Mark Huffer of the Kansas City Area Transit Authority explained that one barrier to transit development is finding qualified transit operators.

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Industry personnel tell me that the high development cost and long approval cycle has been a significant barrier.

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It is now acknowledged that the low literacy rates witnessed in Morocco, and among women in particular, are a major barrier to the process of national socio-economic development.

UNESCO: Country Profile: Morocco

The development of English into the world's lingua franca suggests that spelling is not an insuperable barrier.

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