Complex sentence: In the 21st century, cycling for health, fitness, and as a non-polluting alternative to the automobile has begun to increase in popularity once again, though cycling's transport modal share still accounts for only around 2% of all trips throughout the metropolitan area.
Split into simpler sentences: In the 21st century, cycling for health, fitness, and as a non-polluting alternative to the automobile has begun to increase in popularity once again. Though cycling's transport modal share still accounts for only around 2% of all trips throughout the metropolitan area.