Street Patterns

Street patterns are a feature of urban areas which we can't live without. Street patterns can make it easy to travel around in the city, it can cause heavy traffic congestion or make it very difficult to locate a place.
There are THREE general types of street patterns -

• Grid iron
• Planned irregular
• Cobweb

1. Grid iron:

Usually found in the oldest part of the city (CBD). This pattern is characterized by rectangular street blocks.

Problems:

• Many intersections that can cause traffic congestion
• Uninteresting design
• Can lead to long and steep roads

Advantages:

• Easy to navigate around
• Easy to extend streets
• Easy to subdivide stands and to build on

2. Planned Irregular

Usually found at the latest suburbs and where there are steep slopes.

Problems:

• Difficult to extend streets
• Can easily get lost

Advantages:

• Interesting pattern
• Dangerous with hidden entrances

3. Cobweb

Streets radiate outwards from one central point e.g a plain, lake, dam, park

Where on earth are you?

A geographic coordinate system is a coordinate system that enables every location on the Earth to be specified by a set of numbers. The numbers represent the exact latitude and longitudinal position. If you look at a Gps every object will have a specific position where a latitude and a longitude intersect,

Doesn’t matter where on the earth you find yourself, you will have a latitude and longitudinal position. In South Africa your latitude position will always be south (South Africa is positioned between 22˚ & 35˚ South and 16˚& 33˚ East). Your latitude reference will always be South and longitude reference East. E.g. 27˚38’27’’ S and 30˚18’49’’E.

How do I determine my coordinates on a topographic map?
 
As mentioned before you always give the latitude first and then the longitude.
Step 1: Identify the the object on the topographic map
As mentioned before you always give the latitude first and then the longitude.


Step 1: Identify the object on the topographic map

Step 2: Look at the top of the map and find the latitude (23˚S) and the longitude (33˚E).

Step 3: Find the minutes by looking at the latitude and longitude immediately above (17’) and to the left (25’) of the object. Your coordinate thus far is 23˚17’S and 33˚25’E

You are not yet done, as you need to calculate the seconds.

Step 4: In the grid block where your object is situated measure the following (see diagram)


Latitude: a ÷ A = answer x 60 = C

Longitude: b ÷ B = answer x 60 = D

Therefore, coordinate for spot is –

23˚17’C”South and 33˚25’D”East

 
Latitude: a ÷ A = answer x 60 = C''


Longitude: b ÷ B = answer x 60 = D''

Therefore, coordinate for spot is –

23˚17’C”South and 33˚25’D”East