With thousands of homeless wandering downtown, street dangers in the City By The Bay is now at a constant high level. The recent crime happened when reporters set cellphones, purses and other items in a parked car that were shown on video as they were stolen. The fast-working, window-smashing thieves were not caught.

When travels take you to San Francisco and any other large world city, always obey personal safety rules. Keep your parked car locked, preferably in a commercial garage. Carry wallets in buttoned or zipped pockets. Keep strapped handbags secured under elbows. Always be alert, and at night, walk only with at least one companion on well-lighted busy streets.

They’re called MIA Volunteer K-9 Ambassadors, and human handlers lead them around to stop for friendly visits with people waiting for flights. Similar programs are operated in Los Angeles, Denver and other airports.

Before you reach out to pet an airport therapy dog or any other strange animal, your travel4seniors.com editor has a story to tell. I’ve had furry pets and many encounters with trained working dogs, and never had a problem … until last year’s Halloween night. While attending a street parade, I approached a woman who said her big canine was in training to be a therapy dog.

I petted him, not realizing he was highly stressed from the loud music and crowds. Suddenly he snapped his jaws on my hand, making a large, deep bite. It resulted in an ambulance ride to the hospital and a dozen stitches to close the wound. Conclusion: Whether in an airport or anywhere else, be aware that even the most domesticated and trained dogs are animals. When they’re suddenly nervous or frightened, the attack instinct can take over with painful results.

Consider how costly, tedious and tough it is to travel in busy Las Vegas by taxi and bus. If you’re fit and rarin’ to roam, try wheeling around on a bike. For a 24-hour pass, the cost is just $8, about half the price of a one-way taxi or Uber ride. A three-day pass is just $12, and if you’ll be in town longer, a 30-day pass is just $20. Downtown and many other areas of the city have safe street bike lanes. For more info, go to bikeshare.rtcnv.com

The costs now keep going up. In olden days you paid $10 daily to leave your car at the airport garage while you flew away and returned. Now, daily charges, especially at major airports such as JFK and LAX, can be $40 and up. So, if you spend two weeks on business, touring or visiting relatives, expect to add at least another $560 to your travel costs.

You can avoid the heavy charges and airport hassles of the busy parking garage by going from home to the airport by train, bus, taxi, Lyft or Uber. It may cost $100 total for the round trip, but your wallet and nervous system will thank you for the decision.