Singapore is considered one of the best-designed cities in the world. The man who masterminded it has 2 regrets.

• Liu Thai Ker, 86, is an urban planner who's often considered the architect of modern Singapore.
• He helped build public housing apartments and oversaw the development of the city's land-use plans.
• And yet, he has two regrets: Not creating bicycle paths or preserving squatter settlements.

Towering skyscrapers, candy-colored public housing apartment blocks, and lush green spaces — Singapore has long been recognized for its meticulous urban planning.