That is one reason I do not like the physically restricted lanes. I spent about 15 years riding a lane that for 20 feet had the barrier. A 50 foot stretch got swept maybe twice a year. (They took the barrier down this summer, finally!)

Now when 5' sweepers become common, that changes. (Assuming a "standard" width gets adopted - yea right ) Sounds like a business opportunity for someone. (Do yourself a favor and make the sweep width adjustable.)