Commercial Demand Non-existent

[BruceAtkinson]

Hello all...in the past several weeks, I have noticed something strange.  When I enter a new city tile or even one that I began to build a few months ago, my Demand for Commercial sinks way below what I call the negative line. 
    In a new city, all three indicators are in normal position, until a couple of months pass by, and then the Commercial dips below...does anyone know why this occurs?

[pressus]

The development of cities is associated with various factors, including economic ones, which affect demand - see the game manual.
The neighboring cities in the region have a mutual influence on each other.
If the fluctuations in demand disturb you then apply the appropriate mod that sets the demand for the maximum (it is so brief) 

[BruceAtkinson]

Thanks so much for the input...I realise all that you have said, however this is the first time I 've seen such a fluctuation in one specific category...
    Bruce

[jeffryfisher]

Commercial lots with "low customers" are businesses losing money. They drive down commercial demand. Negative demand bleeds into the whole region.

Never zone any commercial at all until you see enough traffic to rate as high customers. Because traffic patterns can change, you'll sometimes need to dezone whole districts.

Your region probably has some commercial zones somewhere losing money. You need to open up your cities and dezone all of the dead and dying. Run some time off the clock (enough to recalc commute paths) in each so the simulator can absorb the change.

PS: If you've ever messed with a demand mod and then deleted it from an existing region, then all bets are off.

[BruceAtkinson]

...again thanks for this!  Makes perfect sense, and I will scan my region to see if I have any money losing Commercial Districts...and no I have not messed with any mods--I actually thought of that, but no I haven't done so....if interested what I am doing now is re-industrializing a portion of my Region...this Region is the Tampa Bay map.  The extreme Eastern Border is now becoming farming and industrial...light to heavy, especially on the Coastal tiles...and Farming more inland.  At the moment I will continue with that, and at the same time--enter back in to some large established cities to the West of the Region...and check out my Metro Areas for failing Commercial areas....