By bringing the phrase curve balls into the conversation, I am not referring to baseball and having fun playing ball with the team or friends. The matter of grass being blown onto the street can have an effect passersby such as bicycles, pedestrians and especially motorcyclists.
Dangers of Grass Clippings on the Road or Pathway
Far too many hack down their lawn and do not care about it impacting anyone else. They could care less about their lawn and when they finally knock down the grass after it has been growing for six weeks without being cut, they just spray the clippings onto the road. Whether this is deliberately done or due to a serious lack of awareness, it poses a big danger and it must be handled properly. Any one that is walking, jogging, riding a bike or motorcycle through an area where there is grass on pavement is at risk for falling or crashing.
The danger lies within the grass being wet. During the overnight, the moisture content of the air increases, and it abides to the grass. When this happens, a layer of dew forms and the blades of grass are wet. Depending on how tall the grass is, this moisture may not evaporate from the blades of grass all day, even during direct sunlight, especially if it is humid or the grass is incredibly tall. 
What happens when the grass is cut at a high rate of speed from a lawn mower blade, is that the moisture then gets dispersed all over the clippings. Wet clippings on pavement add an element of material between the road surface and the runner or motorcyclist. Road surface is normally grippy for tires on a bike or motorcycle, or the shoes on a runner moving at a high rate of speed, but wet grass prevents those shoes or tires from gripping to the surface. Enough volume of wet grass can cause the pavement area to be as slippery as an ice rink. Talk about danger.
Prevention Is Key
Opinions on this matter scatter across the board. Motorcyclists whose lives could be in danger are generally angry about this, whereas homeowners who want to hack down their yard three times per growing season and “call it good”, do not care about anyone but themselves it appears.
A lawn care service in Stillwater, MN mentioned the technique that is employed by their crews to mow every lawn with one or two passes around the perimeter of the property on their mowers with the discharge chute pointing in towards the lawn. This is not only much safer for the roads and sidewalks, but also reduces the potential for damage to occur to cars driving by the property or pedestrians walking by because the mower deck chutes never point towards them during that time. It also saves them time on every property because their crews do not need to spend time blowing clippings off the street or sidewalk.
They explained their process in-depth in this video:
Another tip that a homeowner could employ, if they have the right mower for the job, is if clippings are blown into the street and they are too lazy to grab a blower to blow it back into the turf, they can drive their mower in reverse with the chute pointing towards the lawn. With blades spinning wide open, unless the turf is completely wet, nearly all of it will blow back into the yard. Saving time and making for a safer environment. An ounce of prevention goes a long way.