For any built environment, circulation is a vital aspect of design. Designing the pathways, and having different levels of circulation to separate the pedestrian and vehicular traffic, is important for a holistic design.
In the days of horse-drawn carriages and vintage cars, streets were designed with cobblestones and were meant more for pedestrians. As trams and buses entered the streets, the streets were widened and a separate pedestrian footpath was designed at the edges.
The modern traffic levels and the multiple usages of streets have resulted in various levels of circulation such as highways, and city-level streets, all the way down to a simple pedestrian footpath.
Streets
Hierarchy of Roads in Urban Planning
- Arterial Roads
- These are the roads at the top of the hierarchy
- They carry the maximum volume of traffic
- They are characterized by the visible segregation of the different directions of traffic movement
- The roads are usually 50-80m and allow speeds of 50-60 km/h and below
- Sub-Arterial Roads
- These roads function similarly to arterial roads, but in areas where access is constrained
- The roads are usually 30-50m and allow speeds of 50 km/h and below
- Distributor/Collector Roads
- They connect the arterial and sub-arterial roads with the access roads
- There is moderate traffic compared with arterial roads
- The roads are usually 12-30m and allow speeds of 30km/h and below
- Access Roads
- They have the lowest traffic capacity
- They are present in localities and used to divide a locality into its layouts
- The roads are usually 15-30m and allow speeds of 15-30km/h and below
- They are characterized by their ability to provide access to an individual building
Design of Streets
- Street Elements
- Footpaths
- The width and height of footpaths should conform to the universal accessibility standards
- The materials used for footpaths should be tough and anti-skid
- There should be drainage provided for rainwater to be cleared off the surface
- There should be no obstructions such as signage, vehicular traffic, furniture, and vegetation.
- If the pathway is along the entrance to a property or at junctions, an appropriate slope should be provided for smooth transitions onto the road and back onto the pavement.
- Footpaths
- Bus Lanes
- A separate bus lane should be provided on roads
- This lane should be closest to the pavement, and bus stops
- The lane can be separated by providing visual segregation or a height difference.
- Parking
- The on-street parking should be done in a way that does not interfere with pedestrian movement
- Curbsides and intersections should be devoid of parking
- Parking should not be provided near bus stops
- A designated space that is indented away from the traffic
- Safety Elements
- Pedestrian crossings
- Signaled pedestrian crossings should be provided at junctions
- The pathway should be defined by zebra crossings
- The space between the “STOP” line and crossing should be 2m
- Tactile paving should be incorporated for the visually impaired
- Pedestrian crossings
- Median and Dividers
- Medians must be placed in the middle of the road to divert the two directions of traffic
- The median must be visible to the driver from their seating position
- The dividers must be temporarily fixed, and removable in case of maintenance or emergencies
- Street Furniture and Lighting
- Seating, trashbin, railings, and signages fall under street furniture
- The seating and railings should follow anthropometric standards
- Seating should be provided under shaded areas
- Traffic signs and other signages must be prominent, and visible to both pedestrians and vehicular traffic
- Street lighting should be diffused and placed at a great height to ensure maximum reach and visibility, without compromising visual comfort
- Multi-Utility Elements
- Plantation
- Plantations on streets are used for the design, functional and aesthetic aspects
- They are used for providing shade to the pedestrians
- They improve air quality
- They reduce ambient heat and surface drain-off
- The greenery makes a street look aesthetic
- Plantation
- Storm Water Management
- Stormwater is collected by an inlet at the edge of the carriageway (path meant for vehicular traffic)
- The water is then transported through pipes to catchment areas
- The natural drainage of water should be enabled by the street design
- The footpath should have a gradient slope towards the shoulder of the street
- Paver blocks and bioswales can help in providing drainage through pores that connect to the soil or pipes
- Public Toilets
- Public toilets are an essential aspect of street design
- The toilets should be designed such that the foul smell is redirected away from the street
- The transition and access from the street and toilet should be easy and efficient
These simple points and tips, when implemented efficiently, can drastically improve a built environment. It is key that the design is universally accessible, the circulation aids in decongestion, and there is aesthetic value.