This summer I learned why Moscow is obsessed with soaking everything in water
I saw the vehicles blast the roadways with high-pressure hose water every day during my trip.
They ran day or night, rain or shine, and as I later learned, they weren't just trying to clean the roads.
The trucks tend to ride side-by-side in fleets, one per lane, and their drivers didn't seem to mind drenching anyone or anything.
If your car window is rolled down and a fleet passes by, the stream can splatter passengers. Riding a motorcycle or a bike? Good luck staying dry.
They're especially feared by pedestrians. If you're walking down the sidewalk during a cleaning, it's not unusual to get your legs and feet drenched with dirty road juices. (I somehow avoided this, but I saw several soaked and unfortunate souls during my travels.)
Here's a clip from a video I recorded of an active spray truck, each of which can hold more than 2,000 gallons of water:
Below is a close-up of another truck I found parked on the street.
You can see one of two big black hoses and nozzles (see arrow), plus what appears to be a hand-held pressure washer. The nozzles are aimed toward the sidewalk when a truck drives by:
Moscow is a post-Soviet capitalistic metropolis, and from my vantage it seemed like citygoers covet cleanliness. So I assumed these trucks drive around to wash grit off the roads.
This is at least partly true, according to an article in The Moscow Times:
After the trucks blast the dirt to the side of the street and sidewalks, city workers on foot come round with brooms and sweep the dirt into piles, later to be collected by trucks. No soap is used, but the pressure the squirters use can scour the streets to toilet-bowl shine.
City workers seemed to be sloshing every square inch of pavement with water buckets and hoses. Few had brushes to scrub the ground; they just seemed to want to make cement and asphalt wet.
I asked a family member who lives in Moscow why workers like to keep their city drenched. In response, he sent me a an article in The Moscow News.
Andrei Khoshtariya, an official for Moscow's road services, allegedly told the outlet in 2011 that during especially hot summer days, cleaning trucks empty their tanks six times a day - up from the typical two cleanings a day.
Why? According to Khoshtariya, this is done in hopes of cooling down the city:
"When the air temperature is higher than 25 degrees [Celsius], we create a microclimate by watering the asphalt, which cools it down[...]"
Let's break apart that logic for a moment, which also seems to extend to the city's efforts to drench sidewalks.
Water is a great coolant. If you splash some on hot surface, it evaporates and carries away the heat. If you spray streets and sidewalks with water, that might be good for cars and tires; the asphalt is cooler.
But what you get is not a cooler microclimate - you'd get a hotter, muggier microclimate.
More water in the air means higher humidity, and this makes your body work harder and sweat more to stay cool. Moscow is fairly dry, so if the microclimate idea really works, this is sort of like turning an arid desert into a steamy jungle.
There's also the energy spent to pump the water and the fuel to drive the cleaning trucks around. It's not a zero-sum game. Trucks generate a lot of heat and belch a lot of carbon dioxide into the atmosphere, which exacerbates climate change - and Moscow stands to warm up significantly from the global phenomenon.
According to the Moscow News article, it's not unusual for the city to dump more than 70 million gallons of water on the road every day during the summer.
That seems like a lot of liquid, effort, and energy to spend in part on a slippery hunch.
If you know an English-speaking employee of MKAD, the agency responsible for Moscow's street cleaning services, please get in touch.