PLANNING ISSUES : PARKING LOT FACILITIES

A parking lot also known as car lot, is a cleared area that is intended for parking vehicles. Usually, the term refers to a dedicated area that has been provided with a durable or semi-durable surface.In most countries where cars are the dominant mode of transportation, parking lots are a feature of every city and suburban area. shopping malls, sports stadium, and similar venues often feature parking lots of immense area.

 

Design and locational considerations

Diagram of example parking lot layout with angle parking as seen from above. White arrows show direction of allowed travel in each lane (for right-hand-drive countries; vice versa in left-hand-drive countries). Several parking spaces closest to the building entrance are reserved for the handicapped. Cars of various colors are shown parked in some of the spaces. The obtusely pointed end indicates the front end of each car.

Parking Area types 

Off-street

Off-street parking is the most common and accepted method of satisfying facility parking needs.When siting off-street parking areas, the designer should consider:

• Creating multiple smaller parking areas rather than one large mass
• Integrating planted islands to increase aesthetics
• Minimize extensive grading operations by designing to the topography
• Ensuring a distance of at least 15 meters is provided from proposed  parking area entrances and exits to intersections.
• Minimizing the number of entrances and exits

On-street

If on-street parking is used, the following factors must be
considered:

• Permit only parallel parking
• Maintain a minimum distance of 15 meters from on-street parking spaces to intersections and offstreet parking area entrances.
• Break up long lines of vehicles with occasional planting island projections if appropriate.
• Ensure streets maintain required traffic-carrying capacities and provide safe vehicular and pedestrian passage.

Off-street Perpendicular Parking

Parallel

For the designer, the parallel parking configuration can be used where suitable off-street parking cannot be accommodated or is not practical. For the driver, parallel parking requires experience, confidence,
and patience.

Advantages
● Works well in extremely narrow, linear spaces
● Requires minimum pavement area

Disadvantages
● Difficult maneuvering for most drivers
● Less than ideal visibility of adjacent traffic
● Inefficient use of on-street space

On-street Parallel Parking

Perpendicular

Especially effective in low turnover rate or long term parking areas, the perpendicular, or 90 degree parking configuration is the most efficient and economical since it accommodates the most vehicles per
linear meter.

Advantages
● Works well with either one- or two-way aisles
● Handles the most vehicles per square meter of pavement
● Handles most vehicles per linear meter

Disadvantages
● Requires widest area
● Difficult maneuvering for some drivers
● Two-way traffic can create some visibility problems

 

                    90 Degree Parking Dimensions and Geometry 

Angled - 60 Degree 

This parking area configuration is ideal for a fast turnover rate or predominantly short term use. This is often offset by difficulties of inefficient circulation patterns and one-way aisles.

Advantages
● Easy maneuvering in and out of parking spaces
● Good visibility
● Lends itself to either one-or two-way aisles
● Most common short term parking configuration

Disadvantages
● Requires more pavement per vehicle than perpendicular configuration
● Handles less vehicles per linear meter

60 Degree Parking Dimensions and Geometry  

Angled - 30 Degree 

Advantages
● Easy parking
● Reduced width requirements for layout

Disadvantages
● Requires the most pavement per vehicle
● Doesn't work well with two-way aisles

 

30 Degree Parking Dimensions and Geometry             

Environmental considerations

Water pollution

Parking lots tend to be sources of water pollution because of their extensive impervious surfaces. Virtually all of the rain (minus evaporation) that falls becomes urban runoff. To avoid flooding and unsafe driving conditions, the lots are built to effectively channel and collect runoff.Parking lots, along with roads, are often the principal source of water pollution in urban areas.

Landscaping

Many areas today also require minimum landscaping  in parking lots. This usually principally means the planting of trees to provide shade. Customers have long preferred shaded parking spaces in the summer, but parking lot providers have long been antagonistic to planting trees because of the extra cost of cleaning the parking lot.


However, parking lots represent significant heat islands and, indeed, heat sinks in urban areas. The heat from paved areas in urban zones has been shown to even have the power to change the weather locally. By providing trees or other means of shading parking lots, the heat and glare resulting from them can be significantly reduced.

Land usage

A parking lot needs fairly large space, around 25 square metres (270 sq ft) times the number of places. This means that parking lots usually need more land area than for corresponding buildings for offices or shops if most employees and visitors arrive by car. This means covering large areas with asphalt.