ENVIS Technical Report: 85 January 2015
http://www.iisc.ernet.in/
Vanishing Lakes Interconnectivity & Violations in Valley Zone: Lack of Co-ordination among Para-State Agencies
 http://wgbis.ces.iisc.ernet.in/energy/
    T.V. Ramachandra*         Bharath H Aithal         Vinay S         Bharath Setturu         Asulabha K. S.         Sincy V.         Sudarshan P.Bhat    
Energy and Wetlands Research Group, Centre for Ecological Sciences, Indian Institute of Science, Bangalore – 560012, India.
*Corresponding author: cestvr@ces.iisc.ernet.in
Effect of Vehicular traffic

The road network is as depicted in figure 12, the nearest main road (Sarjapur road) from the existing construction site behind Kaikondrahalli lake is 1.5 km, with road width of 7.0 m, 2 lanes and 2 way

Figure 12: Existing road network(Source: Google Maps).
Road maximum capacity: As per IRC (Indian Road Congress) for a 2 lane road with traffic flow on both sides, for roads with no frontage access, no standing vehicles, very little cross traffic (intersection) capacity is 1200 PCU/hour (PCU- Passenger Car Unit) (Table 6).


No. of Traffic Lanes and width

Traffic Flow

Capacity in PCU per hour for traffic condition

Roads with no frontage access, no standing vehicles, very little cross traffic

Roads with frontage access, but no standing vehicle and high capacity intersections

Roads with free frontage access, parked vehicles and heavy cross traffic

Two lane  7.0-7.5 m

One way

2400

1500

1200

Two lane  7.0-7.5 m

Two way

1500

1200

750

Three lane 10.5 m

One way

3600

2500

2000

Four lane 14.0 – 15.5 m

One way

4800

3000

2400

Four lane 14.0 – 15.5 m

Two way

4000

2500

2000

6 lane 21 m

Two way

6000

4200

3600

Table 6: Capacity of Urban Roads as per IRC
Source: Highway Engineering. S.K.Khanna & C.E.G.Justo,8th Edition, Table 5.8,pp 191

 

V/C ratio

LOS

Performance

0.0 – 0.2

A

Excellent

0.2 – 0.4

B

Very Good

0.4 – 0.6

C

Average / Fair

0.6 – 0.8

D

Poor

0.8 – 1.0

E

Very Poor

1.0 – 1.2

F

Very Very Poor

Table 7:  Category of Roads based on traffic and service, Source: IRC


For Connecting road between Sarjapur Road and the , with average length of a PCU as 4.5m at an average speed of 35kmph and driver reaction time of 0.7 seconds, the capacity was estimated to be 3094 PCU/hour, on either side of the road, where as for Sarjapur Road, with average length of a PCU as 4.5m at an average speed of 45kmph and driver reaction time of 0.7 seconds, the capacity was estimated to be 3372 PCU/hour, on either side of the road.  Table 8 explains the effectiveness of the road based on the traffic. Due to the dwelling apartments additional 3000 vehicles as PCU is likely to be added


Description of Road

Connecting road

Sarjapura Road

Vehicle speed in kmph

35

45

Average length of vehicle PCU in m

4.5

4.5

Number of lanes

2

4

Driver reaction time in seconds

0.7

0.7

average spacing between vehicles
= (0.278*velocity* reaction time )+ Vehicle Length

11.3

13.3

Theoretical Maximum Capacity of Lane as PCU per lane per hour
= 1000*( Velocity)/( Spacing b/w  vehicles)

3094

3394

PCU Density vehicle/km/lane
= Number of Vehicles per hour/Vehicle speed

88

75

Maximum capacity flow occurs when speed is Velocity/2 and Density is PCU Density/2 (or Jam Density)
Maximum flow of traffic as number of PCU per lane per hour per km
= Velocity/2 * PCU Density/2

770

843

Length of the road

1.8

0.8

Maximum flow as vehicles per km per hour

2310

2697

Peak Hour Traffic

800

2000

Current Vehicular Traffic to Maximum Capacity Ratio (ratio of peak hour traffic to maximum flow)

0.34

0.74

Current Level of Service

Good

Average

Additional Vehicles as PCU due to the apartments

2000

Additional Vehicles added to traffic per hour

800

800

Number of Vehicles due to addition

1600

2800

Vehicular Traffic to Maximum Capacity Ratio due to addition of new vehicles

0.69

1.04

Level of Service due to the additional vehicles

Average

Very Very Poor

Reference: Highway Engineering. S.K.Khanna & C.E.G.Justo
[Assumption: 800 PCU/hour addition during peak hours for 3 hours (example : 8 AM to 11 AM)]

Table 8: Vehicular Traffic

The equivalent ratio of V/C (Table 7) to the LOS is D and F respectively for the connecting road and the Sarjapur road, indicating very poor traffic conditions, creating bottle necks. The probable bottle necks are as depicted in figure 13.

Figure 13: Bottlenecks