[drac]

they need constant care and monitoring - especially after heavy storms or bad weather of any sort, really.

The tree lined boulevards in my city routinely disrupt traffic after monsoon rains - most are close to 40 years old, and every so often will shed a branch or three onto the road.

[einhverfr]

Depends on the tree and type of maintenance. Some monitoring and directional pruning goes a long way. In general the larger the tree the more maintenance and monitoring is required.