If you are a beginner to bicycle meditation, you might want to deliberately pick out a quiet place for your first meditation ride or two. Here are some suggestions:
As you can see, you can turn a riding environment you might think to be a handicap into a bonus through meditating on your bike. "Yuk, I can't ride — it's raining!" you think. But after you dress right, when you get on the bike in the rain, you can use the weather as a focus for meditation. Just spending a ride feeling the rain hitting your face can transform how you regard rainy-day riding.
Nighttime, too, can be a wonderful time for bicycle meditations. While you get a lot of visual information that enhances your safety while riding during the day, you also get lots of visual distractions, too. Nighttime riding reduces your visual field to just what's important — what is being illuminated by your riding lights. With so fewer other vehicles at night, particularly on trails, you can focus on other aspects of your being on the bike.
You don't have to ride, though, where the traffic is extremely light or non-existent, to benefit from bicycle meditation. Most rides aren't ones where you can completely ignore the road, but they also aren't ones where you have to put 100% of your focus on traffic, either. More likely, your daily ride is like mine, where you have times when you have to really pay attention to traffic and hazards, and other times when you don't. These kinds of environments are fine for meditation.
If you have to watch the road carefully at times at the beginning of your meditation, it might feel like an interruption. That's okay, let yourself be interrupted — there's plenty of time to go back to your pedals, back to your breathing. Further in the ride, though, the road hazards aren't interruptions, they're just what's happening. In fact, you can respond more quickly and smoothly to them because you are in this aware state. You may find yourself picking times to meditate when traffic is higher, rather than lower, to experiment with how this feels for you, inside and out.