(...from a Bostonian's perspective)

While exploring the urban landscape of San Francisco this summer, one thought that I've had that has really intrigued me is the sense of urban scale that exists in San Francisco and 'urban morphologically' speaking gives San Francisco a very unique 'Street DNA'. This today was interestingly pronounced on my varied daily journey between several different SF neighborhoods and respective travel.

My neighborhood itinerary for today's agenda was as follows:

Hayes Valley (start: sisters apartment)
walk to Market (for MUNI)
get off at Union Square
walk to REVIT class in southern SOMA
Walk from class back via Yerba Buena garden & Academy of Art
Walk to Trans America building in the financial District
Take the Cable Car up California St. towards Nob Hill (passing China Town)
Get off Cable Car and walk from Nob to Russian Hill (end: home)

While this is also a unique list of transit options, what really stood out during this experience was the different neighborhood scales.

The Grid

San Francisco is overwhelmingly (99%) a grid system which begins to afford a certain nature of street geometries. While there are certain neighborhoods that break this rule (generally from a particular era of planning), I would classify the overwhelming majority of San Francisco (or the places that people typically go and function in a highly urban sense) as Grid.

Even Market Street, the street that breaks the grid, has a certain logic to it that enhances the grid (connections between skewed SOMA and Financial District line up for clean connections with block length adjusted correspondingly). In many cities, diagonal streets similar to Market would leave an overwhelming amount of unresolved geometric discrepancies that would remain rough.

Here comes to Automobile...

What runs as a common element throughout all of the neighborhoods of SF is the fundamental scale of the personal automobile. Although some of SF's most densest neighborhoods remind me a lot of the density of Boston, the largest difference is that they are still at a scale that corresponds to the automobile. Cities like Boston on the other hand have extremely dense neighborhoods that were retrofitted for the automobile and therefore sacrifice pedestrian space to enable unencumbered vehicular traffic with little to no sidewalk space. San Francisco's 'dense' financial district has no such problem accommodating appropriate amounts of vehicular traffic while still having ample sidewalk space for pedestrians. Greatly proportioned street sections accommodate 4-5 lanes of traffic (and parking), 10-12 ft. sidewalks accommodate peak pedestrian flows, and a decently sized landscape buffer mitigates the two.

Even Chinatown which follows the automobile rule the least and accommodates very little automobile traffic during the day obey's the grid and keeps to an auto-centric proportion. (Chinatown has some of the most pedestrian trafficked street's in all of San Francisco. Only rivaled by Powell between Market & Union Square, and Castro St. on weekend nights).

Interestingly enough, these 'well proportioned streets' do create somewhat of an urban paradox that might not be entirely positive for vibrant street life. Although the ample amount of space allows traffic to remain segregated and separate which somewhat leads to SF's strong auto-centric driving culture whereas in cities like Boston where Pedestrian and vehicular space must be shared. Shared space between modalities requires all users to work together to achieve the common goals of individual transit. In this sense, modality users must respond to traffic appropriately: cars slow down (USUALLY ) while pedestrians move out of the way of queued cars (when convenient).

***Caveat: I admittedly am biased towards the pedestrian, and have very limited automobile experience in this neighborhood. My few trips in a car in SF's financial district did seem incredibly frustrating as lights aren't typically timed for automobiles and any turn requires a significant wait to allow pedestrian crossings (this is universally common in all urban central business districts).

This is where bikes come in...

Overall Density

Overall, I find it fascinating that although streets in San Francisco tend to be of automobile scale while Boston's are completely oblivious to automobile scale while cramming traffic in to narrow street's, the overall density of SF's financial district still feels strangely similar to the scale of Boston's financial district (I'm curious to see if there is a similar FAR in these two instances).

SOMA tends to related very strongly with Boston's waterfront (or 'Innovation District') or the new development of the Fenway neighborhood.