MOBILITY AND ACCESSIBILITY PROBLEMS OF ELDERLY DRIVERS IN INDIA
Chakrabarty , Neelima 1 / Mittal,Nishi 2 / Parida, Purnima 3CSIR- Central Road Research Institute,Mathura Road,New-Delhi,India
/ /
Abstract: Accessible transportation is the passport to independent living for everyone. To achieve maximum economic gain every country needs maximum mobility between and within country. The hindrance of mobility of any population group e.g. elderly or impaired, reduces economic growth some way or the other.
Many countries estimate that about 12-14% of their population is disabled in some way and 5-10% has walking or mobility difficulties. Elderly people with mobility, sensory and cognitive impairment face many challenges in daily life. Aging causes physiological changes that make driving more difficult, these include increased reaction time, deteriorating vision (particularly at night) ,and a reduced ability to split attention between several tasks.
This study highlights following objectives:
a) To study the hand grip strengths of the drivers’ and tremors movements with increasing age ,elderly motorist problems b) To study Visual Recovery Time from constant and interval glares with increasing age
Methodology: 250 drivers belonging to Delhi and NCR areas were randomly selected for the present study. These drivers were tested for Hand Steadiness Test and Grip Test in the field. Drivers were randomly selected and they were administered Glare Test (Constant and Random Glares) in laboratory. Findings of the studies highlight that a) Hand grip strengths of the drivers’ decreases and tremors movements increases with increasing age b) Visual Recovery Time from constant and interval glares.
1.Introduction
For a developing country like India, the rapid growth in the number of older population and related issues must be addressed if social and economic development is to proceed effectively. Unlike in the western countries, where there is dominant negative effect of modernization and urbanization of family, the situation in the developing countries like India is in favour of continuing the family as a nuclear for performing various activities (Siva Raju, 2000, 2002, 2004). In spite of several economic and social problems, the younger generation generally looks after their elderly relatives. Though the young generation takes care of their elders in traditional societies, it is their living conditions and the quality of care, which widely differs from society to society.
1.3. Correlation between Age and Psychophysical Factors Affecting the Road Safety
Driving is a serious responsibility and it demands and deserves full and undivided attention of the driver. With the increase in age all road users come under greater risk of experiencing deficits in the various functional abilities needed to drive safely. The Maryland Pilot Older Driver Study highlights that loss of key functional abilities among elderly drivers is associated with an increase in motor vehicle crash (Staplin L. et al 2003 a, b). These function abilities are as following:
• Visual skill (seeing): These include the visual abilities needed to detect hazards, while effectively directing attention to critical driving tasks in the face of mounting distractions. Also essential are the perceptual skills needed to accurately judge gaps in traffic and the cognitive functions necessary to make rapid and appropriate maneuver decisions. Watching the road in front and around the vehicle, using mirrors, shoulder checks, checking gauges, speedometer, etc.
• Auditory skill (listening): Squealing of brakes, the sirens of an emergency vehicle, vehicle sounds, etc.
• Bio-mechanical (performing hand–eye co-ordination): These abilities include hand–eye co-ordination which require head and neck flexibility to scan for safety threats before turning, backing up, changing lanes, or merging, as well as arm and leg strength and stamina needed for effective control of the vehicle under normal and emergency response conditions
• Cognitive (thinking): Anticipating any future movements, dynamic route planning, assessing situations such as movements of other vehicles, weather conditions, preparing to avoid hazards, etc.
1.4. Causes of Visual Problems due to Aging
Although there are neural losses, the major decline is due to changes in the eye's optics. First, the lens becomes yellower, making discrimination of blue colors more difficult. More importantly, less light entering the eye reaches the photoreceptors. One problem is that the lens and other optical media become opaque. Further, the pupil shrinks, allowing less light to enter the eye. The following table shows how the pupil size shrinks with age. Note that the pupil's response to dim light also decreases with age and becomes virtually nil by age 80. This means the elderly have especially large vision problems in low light environments.
As a result of all these factors, at age 60, the amount of light reaching the photoreceptors is only 33% of the amount seen at age 20. By the late seventies, the amount falls to 12%. Further aging reduces light transmission even more as the effect accelerates.
1.4.1. Contrast Sensitivity: As a result of these factors, contrast sensitivity declines with age. The graph below shows how contrast must be increased with age. Using the sensitivity of a twenty year old as the base line, the graph shows the factor by which contrast must be increased in order to maintain visibility level. Required contrast increases gradually to a factor of two in the 60's. The loss of contrast sensitivity then accelerates, reaching a factor of six by age 80.
1.4.2. Light and Dark Adaptation: The eye adjusts when moving from light to dark or dark to light environments. For example, when we drive into a tunnel, we go from the relatively bright outdoor light level to a dimmer visual environment. The speed with which the eye adjusts to this change is called light adaptation. Aging causes a marked decrease in the speed of light adaptation, so older drivers are almost blind during such transitions.
1.4.4. Motion Perception: Studies of motion perception usually find some loss for older people, especially when judging very slow or very fast motion.
1.4.5. Restricted Field of View: When driving, the drivers spend most of the time looking straight ahead but are still able to notice objects in the visual periphery. Older drivers lose some of the ability to see objects off to the side and have a restricted "functional field of view."
1.4.7. Reaction Time: Older people are slower to respond when driving. The best estimate is that they are about 0.2-0.3 seconds slower than younger drivers. However, as tasks become more complex, the effect of aging may be bigger.
1.5. Functional Problems of Older Drivers: Cynthia et al 1998 reported a study organized by The National Institute on Aging in a symposium where 400 older drivers could explain their biggest difficulties in driving. The general consensus was that they had particular problems merging with traffic. There were also problems seeing the peripheral field, and they had difficulty noticing the unexpected appearance of vehicles away from the direct line of sight.
1 .a) Study of the Hand Grip Strengths of the Drivers’ And Tremors Movements With Increasing Age
This study was conducted at CSIR-CRRI for the testing the hand grip capacity and hand tremor of the drivers .Around 300 drivers randomly selected for this test across all age groups. The sample was administered hand grip test which measures The study showed that hand grip decreased and hand (tremor) increased with age of the drivers (table-1).
Table-1 The Table showing Grip Test and Hand Tremor test of the drivers
Age-Groups / Grip Test (Kg) / Hand - Tremor Test (Hole Completed)>18-21 / 53 / 7
>21-25 / 53 / 6
>25-35 / 53 / 6
>35-45 / 50 / 6
>45-60 / 43 / 5
b) The Opinion Survey of the Elderly Motorists Problems
CSIR - Central Road Research Institute has carried out an opinion survey in 2011 on elderly motorists to highlight various to find out their views and the problem faced by them during driving and the driving facilities available to them on Delhi city, in which around 50 motorists were interviewed. The sample was consisted of 84% male and 16% female motorists of 50-60 years (50%); 60-70 years (40%) and 70 years and above (10%).
2.1. Overall Satisfaction Level of the Elderly Motorists
The elderly motorists were surveyed to know whether the prevailing facilities and conditions for motorists were conducive to their needs and requirements (Fig 1). It was revealed that 80 percent of the motorists were not satisfied with driving scenario. In the survey 88% females found it rather difficult to drive partly because of increasing age and because of poor road conditions in Delhi.
2.2. Visibility Aspects of Road Signs and Signals: It was observed in the survey that the visual problems increase with the age of the individual as more aged motorists were complaining more vision related difficulties i.e. 60% among the 70 years and above age groups as compared to 35% and 20% of the 50-60 yrs and 60-70 yrs group respectively. Older adult drivers, because of their age-related deterioration of visual functions, need more contrast, a higher level of background luminance and larger letter sizes than younger drivers to achieve the same level of comprehension (Malfetti, et al ,1987; Taoka, G.T. ,1991).
2.3. Problems Due to Long Driving Hours: Around 88% of the total motorists surveyed opinioned that they like to avoid long driving hours.
2.4. Problems of viewing Left Turn Signs: The motorists were interviewed for difficulty in left hand turning movements. It was observed that around half of the total motorists (48%) avoided taking left turns .The reasons they expressed that they found high traffic (40%), difficulty in neck and eye movements (22%), and poorly designed left hand turning signs (38%) . Moreover, female motorists were accounted for almost double for difficulty in neck and eye movements; 38% females versus 19% males. This can be explained by the medical fact that old age deterioration is more in females with respect to neck movements and muscle straining due to driving (Hunter , et al. 29 May. 2008;Medscape. 2009).
2.5 Feeling Safety While Driving: Motorists were asked about how safe they feel while driving on Delhi roads. Around 70% from all the motorists from the present sample population, felt that driving hazards on roads have increased over the last five years and this scenario has become worse for the elderly drivers especially due to rise in traffic and reckless behavior of fellow motorists. Older females found driving on roads to be more unsafe than the males of the same age group. Around 75% female motorists felt unsafe while driving as compared to 69% male motorists.
2.6. Avoiding High Speed Corridors: It was also observed that often elderly motorists avoid using high speed routes and highways. Most of the motorists (31 %) felt that reckless drivers are the biggest hazard for them on the road. The other reasons for them were high traffic (26%), difficulty in driving (11%), reduced strength (9%) and poor psychomotor abilities (8%) (Fig 2).
2.7. Parking Problems: Around two-fifths (40%) of the male motorists from the present sample felt difficulty in parking comfortably as compared to 75% of the female motorists. The reasons for such opinion they expressed were poorly designed parking facilities around the city and reduced strength among the elderly group. Females considered reduced strength (63%) as the major reason for discomfort while parking.
2.8. Judgment and Understanding of Road Traffic: Around 72% of the motorists stated that their judgment and understanding of road traffic has changed over the years. But the studies done by Hakamies-Blomqvist, Raitanen, & O'Neill, 2002 highlighted that older drivers are as good in certain driving characteristics as younger drivers.
2.9. Comfort level of Seatbelts While driving: 40% of the elderly motorists were ignorant about this. On the other hand, elderly female car drivers considered wearing seatbelt as an important safety precaution. Around 27% had comfort issues with seatbelt i.e. they had an opinion that seatbelts are “Uncomfortable”. Finally18% of them gave the reason as it is not compulsory to wear.
2.10. Comfort along with the passengers while driving: Almost all the female car drivers considered driving along with a passenger to be safer, two thirds of the male elderly motorists preferred to drive with passengers. It was probably because elderly drivers felt more confident with the passengers who serve as an extra assistance when conditions are perceived as more dangerous.
Part 2. Study of Visual Recovery Time from Constant and Interval Glares with Increasing Age
This study was conducted done by CSIR-CRRI (Chakrabarty et al, 2002) highlights that visual recovery period increase with the age of the drivers. The study was conducted on one hundred and fifty car drivers across different age groups i.e. up to 25 years (Group I); 26 to 40 years (Group II); 41 to 50 years (Group III); 51 years and above (Group IV). These subjects were exposed to different glare conditions with the help of in laboratory equipment (Computerized Driver Evaluation Tester). This has been analyzed that mean visual recovery time (in seconds) increases with age (table-2).
Age Group / Group I / Group II / Group III / Group IVMean Visual Recovery Time from Glare / 2.68 / 4.99 / 5.93 / 11.33
Table2: Mean Values of Age factor on Visual Recovery period