Study on trip generation characteristics of new apartment buildings in the Colombo city

Abstract

Colombo city as the economic hub of Sri Lanka is attracting more and more people day by day and most of them wanted to settle nearby Colombo city. Therefore, many high-rise apartment buildings have been constructed and many more projects are planned in and around Colombo. Currently, an apartment building can be classified as low, middle or high-income based on the prize of the unit and the facilities provided for the housing unit. The impact of traffic generated by each category varies with the frequency, time and mode of vehicle travel. In general, generalizing the travel patterns of apartment buildings is quite difficult as it has highly distributed traffic flow throughout the day. There are many land use activities that can affect the flow of neighbourhood traffic, but this research is limited to study the impact on traffic flow by residential developments in operational phases. The impact of different types of apartment buildings on traffic flow and trip generation rates is very important and useful in making decisions. However, when consider the Sri Lankan context there is no comprehensive study to measure those details. As per the existing practice, the parking demand of the apartment building is estimated based on the unit floor area and no standards have been developed to estimate the trip generation of different type of apartments. Therefore, this study aims to study the trip generation rates for each apartment type and the most suitable parking requirements for different apartment types. During this study, apartments were selected under three main categories as Low, middle and high income category based on the available facilities and unit price. For this study, 15 apartments as 5 from each category spread over the Colombo Municipal Council area, were selected. The number of occupied housing units, vehicle ownership rate, number of visitors and visitor’s vehicle composition were collected by an on-site observation survey, while traffic counts and vehicle composition were collected by a traffic survey. Satisfaction level of the unit owner on the parking facilities provided was collected via questionnaire survey. Trip generation rate per apartment unit and mode of the vehicle were analyzed individually and compared with each apartment type. Correlation analysis was conducted to study the relationship between trip generations against average unit floor area, average number of bedrooms in occupied units and unit price were analyzed to identify suitable parameter to determine parking requirement of a housing unit. A unit owner’s perception was analyzed to check visitor’s parking requirements. During the analysis, it was found that middle income apartments have reported overall highest trip share percentage in morning and evening peak while high income and low income apartments are taking 2nd & 3rd place respectively. Low income apartments have reported high trip share in the day time while high income reported lowest trip share Middle income apartment has the highest per unit trip generation rate. When consider the vehicle composition, car has reported the highest percentage in each apartment category with the highest percentage in the middle income category. The only unit floor area was found as a suitable criteria for determining traffic generation or parking requirement of an apartment unit, but the average unit price and number of bedrooms per unit are found not significant. Vistor’s parking space requirement for cars is between five to ten percent of the total parking requirements while lesthan five percent is enough for motorcycles and three wheels